msvc: Append the default .pdb extension for the /Fd argument

[ikolomiko]

MSVC appends the .pdb extension for the file path given for the /Fd argument, if the extension is omitted. This commit adds this functionality for feature parity.

Fixes #2620

[codecov-commenter]

Codecov Report

❌ Patch coverage is 68.00000% with 40 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.37%. Comparing base (0efe890) to head (782d55c).
⚠️ Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
src/compiler/msvc.rs	68.00%	40 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2621      +/-   ##
==========================================
- Coverage   73.40%   73.37%   -0.03%     
==========================================
  Files          68       68              
  Lines       37219    37337     +118     
==========================================
+ Hits        27320    27397      +77     
- Misses       9899     9940      +41     

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[codspeed-hq]

Merging this PR will not alter performance

✅ 60 untouched benchmarks
⏩ 4 skipped benchmarks¹

---

_{Comparing ikolomiko:main (782d55c) with main (0efe890)}

Footnotes

1. 4 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[AJIOB]

@ikolomiko, please, recheck the format: looks like it's failed

[ikolomiko]

Oopsies, fixed it

[AJIOB]

Nice! Can you add the test for that, please?

It will help with unexpected regression

[AJIOB]

Tests, please

[ikolomiko]

@AJIOB sure, here it is!

[ikolomiko]

Looks like the ci pipeline is borked :d