2023.3/platform/windows/uum-62035 to unity-2023.3-mbe

[TautvydasZilys]

Backport of #2003

Fix marshaling/interop code emitting ldloc 65535 instruction when calling method on a COM interface. This happened due to unitialized local variable (gc_safe_transition_builder.coop_cominterop_fnptr) getting loaded when "need_gc_safe" is false. This caused the JIT to throw an InvalidOperationException. This fixes case UUM-62035. This bug was indirectly introduced by a previous pull request, which optimized interop call performance and made us take another code path which turned out not to work with COM interop: #1753.

• Should this pull request have release notes?
  • Yes
  • No

Reviewers: please consider these questions as well! ❤️

Release notes

Fixed UUM-62035 @zilys
Mono: Fixed InvalidProgramException (Invalid IL code in (wrapper managed-to-native) : IL_0004: ldloc 65535)
getting thrown when calling COM interop methods,

Unity repository changes

I added a test for this change on this branch: https://github.cds.internal.unity3d.com/unity/unity/commits/platform/windows/uum-62035. Preferably this test gets merged to trunk together with this bugfix.

[unity-cla-assistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}