Boost\libs\python failed to build due to link error on MSVC

使用 .\bootstrap、兩個 .\b2 建置命令，以及最後的 .\b2 ... libs\python\test 命令，在 VS 2019 x64 命令提示字元中重現此失敗。檢查產生的連結回應和 Boost.Python 建置設定；當回報的 MSVC 建置與測試目標成功完成連結時，即表示完成。

Issue description:
Boost\libs\python failed to build due to link error on MSVC. Could you please take a look?

Build step:

1. git clone -c core.autocrlf=true --recursive ​https://github.com/boostorg/boost.git D:\Boost\src
2. open a VS 2019 x64 command prompt and browse to D:\Boost\src
3. .\bootstrap
4. .\b2 headers variant=release --build-dir=..\out\x64rel address-model=64
5. .\b2 variant=release --build-dir=..\out\x64rel address-model=64
6. .\b2 -j4 variant=release --build-dir=..\out\x64rel libs\python\test

Error info:
F:\gitP\boostorg\boost\linkrepro>link @link.rsp
Creating library .\builtin_converters_ext.lib and object .\builtin_converters_ext.exp
builtin_converters.obj : error LNK2001: unresolved external symbol __std_terminate
builtin_converters.obj : error LNK2019: unresolved external symbol __imp__invalid_parameter_noinfo_noreturn referenced in function "void * __cdecl std::_Allocate_manually_vector_aligned(unsigned __int64)" (??$_Allocate_manually_vector_aligned@U_Default_allocate_traits@std@@@std@@YAPEAX_K@Z)
builtin_converters.obj : error LNK2019: unresolved external symbol __std_exception_copy referenced in function "public: __cdecl std::bad_alloc::bad_alloc(class std::bad_alloc const &)" (??0bad_alloc@std@@QEAA@AEBV01@@Z)
MSVCRT.lib(throw_bad_alloc.obj) : error LNK2001: unresolved external symbol __std_exception_copy
builtin_converters.obj : error LNK2019: unresolved external symbol __std_exception_destroy referenced in function "public: virtual __cdecl std::bad_array_new_length::~bad_array_new_length(void)" (??1bad_array_new_length@std@@UEAA@XZ)
MSVCRT.lib(throw_bad_alloc.obj) : error LNK2001: unresolved external symbol __std_exception_destroy
builtin_converters.obj : error LNK2019: unresolved external symbol __std_type_info_name referenced in function "struct boost::python::detail::signature_element const * __cdecl boost::python::detail::get_ret<struct boost::python::default_call_policies,struct boost::mpl::vector1 >(void)" (??$get_ret@Udefault_call_policies@python@boost@@U?$vector1@H@mpl@3@@detail@python@boost@@YAPEBUsignature_element@012@XZ)
builtin_converters.obj : error LNK2019: unresolved external symbol _CxxThrowException referenced in function "void __cdecl std::_Throw_bad_array_new_length(void)" (?_Throw_bad_array_new_length@std@@YAXXZ)
MSVCRT.lib(throw_bad_alloc.obj) : error LNK2001: unresolved external symbol _CxxThrowException
builtin_converters.obj : error LNK2001: unresolved external symbol __CxxFrameHandler4
MSVCRT.lib(gshandlereh4.obj) : error LNK2001: unresolved external symbol __CxxFrameHandler4
builtin_converters.obj : error LNK2019: unresolved external symbol memcpy referenced in function "public: __cdecl std::basic_string<char,struct std::char_traits,class std::allocator >::basic_string<char,struct std::char_traits,class std::allocator >(class std::basic_string<char,struct std::char_traits,class std::allocator > const &)" (??0?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QEAA@AEBV01@@Z)
MSVCRT.lib(new_scalar.obj) : error LNK2019: unresolved external symbol _callnewh referenced in function "void * __cdecl operator new(unsigned __int64)" (??2@YAPEAX_K@Z)
MSVCRT.lib(new_scalar.obj) : error LNK2019: unresolved external symbol malloc referenced in function "void * __cdecl operator new(unsigned __int64)" (??2@YAPEAX_K@Z)
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __vcrt_initialize referenced in function __scrt_initialize_crt
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __vcrt_uninitialize referenced in function __scrt_initialize_crt
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __vcrt_uninitialize_critical referenced in function __scrt_dllmain_uninitialize_critical
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __vcrt_thread_attach referenced in function __scrt_dllmain_crt_thread_attach
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __vcrt_thread_detach referenced in function __scrt_dllmain_crt_thread_attach
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _seh_filter_dll referenced in function __scrt_dllmain_exception_filter
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _is_c_termination_complete referenced in function __scrt_dllmain_uninitialize_c
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _configure_narrow_argv referenced in function "public: static int __cdecl __scrt_narrow_argv_policy::configure_argv(void)" (?configure_argv@__scrt_narrow_argv_policy@@SAHXZ)
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _initialize_narrow_environment referenced in function "public: static int __cdecl __scrt_narrow_environment_policy::initialize_environment(void)" (?initialize_environment@__scrt_narrow_environment_policy@@SAHXZ)
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _initialize_onexit_table referenced in function __scrt_initialize_onexit_tables
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _register_onexit_function referenced in function _onexit
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _execute_onexit_table referenced in function __scrt_dllmain_uninitialize_c
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _crt_atexit referenced in function _onexit
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _crt_at_quick_exit referenced in function at_quick_exit
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __acrt_initialize referenced in function __scrt_initialize_crt
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __acrt_uninitialize referenced in function __scrt_uninitialize_crt
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __acrt_uninitialize_critical referenced in function __scrt_dllmain_uninitialize_critical
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __acrt_thread_attach referenced in function __scrt_dllmain_crt_thread_attach
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol __acrt_thread_detach referenced in function __scrt_dllmain_crt_thread_detach
MSVCRT.lib(utility.obj) : error LNK2019: unresolved external symbol _cexit referenced in function __scrt_dllmain_uninitialize_c
MSVCRT.lib(utility.obj) : error LNK2001: unresolved external symbol __C_specific_handler
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_CloseHandle referenced in function "void __cdecl __scrt_uninitialize_thread_safe_statics(void)" (?__scrt_uninitialize_thread_safe_statics@@YAXXZ)
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_EnterCriticalSection referenced in function _Init_thread_abort
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_LeaveCriticalSection referenced in function _Init_thread_abort
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_InitializeCriticalSectionAndSpinCount referenced in function "int __cdecl __scrt_initialize_thread_safe_statics(void)" (?__scrt_initialize_thread_safe_statics@@YAHXZ)
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_DeleteCriticalSection referenced in function "void __cdecl __scrt_uninitialize_thread_safe_statics(void)" (?__scrt_uninitialize_thread_safe_statics@@YAXXZ)
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_SetEvent referenced in function _Init_thread_notify
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_ResetEvent referenced in function _Init_thread_notify
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_WaitForSingleObjectEx referenced in function _Init_thread_wait
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_CreateEventW referenced in function "int __cdecl __scrt_initialize_thread_safe_statics(void)" (?__scrt_initialize_thread_safe_statics@@YAHXZ)
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_GetModuleHandleW referenced in function "int __cdecl __scrt_initialize_thread_safe_statics(void)" (?__scrt_initialize_thread_safe_statics@@YAHXZ)
MSVCRT.lib(utility_desktop.obj) : error LNK2001: unresolved external symbol __imp_GetModuleHandleW
MSVCRT.lib(thread_safe_statics.obj) : error LNK2019: unresolved external symbol __imp_GetProcAddress referenced in function "int __cdecl __scrt_initialize_thread_safe_statics(void)" (?__scrt_initialize_thread_safe_statics@@YAHXZ)
MSVCRT.lib(tncleanup.obj) : error LNK2019: unresolved external symbol __imp_InitializeSListHead referenced in function "void __cdecl __scrt_initialize_type_info(void)" (?__scrt_initialize_type_info@@YAXXZ)
MSVCRT.lib(tncleanup.obj) : error LNK2019: unresolved external symbol __std_type_info_destroy_list referenced in function "void __cdecl __scrt_uninitialize_type_info(void)" (?__scrt_uninitialize_type_info@@YAXXZ)
MSVCRT.lib(delete_scalar.obj) : error LNK2019: unresolved external symbol free referenced in function "void __cdecl operator delete(void *)" (??3@YAXPEAX@Z)
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_RtlCaptureContext referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_RtlCaptureContext
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_RtlLookupFunctionEntry referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_RtlLookupFunctionEntry
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_RtlVirtualUnwind referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_RtlVirtualUnwind
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_IsDebuggerPresent referenced in function __scrt_fastfail
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_UnhandledExceptionFilter referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_UnhandledExceptionFilter
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_SetUnhandledExceptionFilter referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_SetUnhandledExceptionFilter
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_GetStartupInfoW referenced in function __scrt_get_show_window_mode
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __imp_IsProcessorFeaturePresent referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2001: unresolved external symbol __imp_IsProcessorFeaturePresent
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol terminate referenced in function __scrt_unhandled_exception_filter
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __current_exception referenced in function __scrt_unhandled_exception_filter
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol __current_exception_context referenced in function __scrt_unhandled_exception_filter
MSVCRT.lib(utility_desktop.obj) : error LNK2019: unresolved external symbol memset referenced in function __scrt_fastfail
MSVCRT.lib(gs_report.obj) : error LNK2019: unresolved external symbol __imp_GetCurrentProcess referenced in function __raise_securityfailure
MSVCRT.lib(gs_report.obj) : error LNK2019: unresolved external symbol __imp_TerminateProcess referenced in function __raise_securityfailure
.\builtin_converters_ext.pyd : fatal error LNK1120: 59 unresolved externals