Can't Diff and Port same named executables at the same time

Start by reproducing the failure with two concurrent BinDiff sessions using same-named IDBs, following the described diff and port workflow on Windows with IDA 7.5 or 7.6. Trace how BinExport, BinDiff, and the shared temporary database name their files and isolate the collision point. Done means two simultaneous diff-and-port operations complete without failure or corruption.

Do to the way Binexport and/or Bindiff names it's temp files, you can not successfully do more than one diff and/or port at the same time.

The problem is because the tools use the same temp folder and the temp DBs that are created have the same names since they use the the original base name of the executable. Plus a common/global DB named "temporary.database" is already in use.

Example session for the IDB name problem:
If you made an IDB of an executable named "foobar.exe" and saved it "foobar_a.exe.i64" and another of the same named exe (from an update or something) "foobar_b.exe.i64" the tools will name them all "foobar.BinExport" since the tools name these internally based on the base name.
Normally not a problem for a single IDB operation since the DB files are separated path structure "BinDiff\primary" and "BinDiff\secondary". But if you open one more additional sessions (different "ida64.exe" processes) with "foobar_aa.exe.i64" and "foobar_bb.exe.i64" now the conflict exists because these names are taken plus "temporary.database" is already used.

Steps to reproduce the problem:

1. The normal modus operandi, BinDiff an older executable with a new then port symbols and comments using the port feature. But attempting to do more than one at the same time.

What is the expected behavior?
Expected to be able to Diff and port two different IDA IDBs at the same time on the same machine.

What went wrong?
At least the port feature will fail when it is started, and probably results in diff corruption.

What version of the product are you using? On what operating system?
"BinDiff 7 (latest version, updated)", IDA 7.6 and IDA 7.5 on Windows 10 21h1

Any other comments?
As a solution, consider adding a top level root folder called "Session438" or something where the "438" number is the PID of the host "ida64.exe". An easy way to serialize the the folder structure with a UUID.

Ported from b/200299139