Support interfacing with debuginfod from binutils

With GNU Binutils 2.34 comes debuginfod support, which is the HTTP server catching our eye while the debuginfod server is distributed as part of the latest elfutils package. This isn't for a general purpose web server thankfully but is an HTTP server for distributing ELF/DWARF debugging information and source code. With debuginfod enabled, Binutils' readelf and objdump utilities can query the HTTP server(s) for debug files that cannot otherwise be found. Enabling this option requires building Binutils using --with-debuginfod.

See https://developers.redhat.com/blog/2019/10/14/introducing-debuginfod-the-elfutils-debuginfo-server/ for more information.