Invalid Paths in generated PDB files

[asgardkat]

Zig Version

0.12.0-dev.890+8c6b0271c

Steps to Reproduce and Observed Behavior

Create a shared library with a zig file in a subfolder (say src/test/test.zig) and ensure it is being used so it's not stripped.
Observe the generated PDB file, it will have a reference to say D:\Development\ZigSandbox\src\test\test\test.zig instead of D:\Development\ZigSandbox\src\test\test.zig, adding the final directory twice.

This worked correctly in 0.12.0-dev.817 so looks like some kind of regression.

Expected Behavior

The embedded path should be correct.

[asgardkat]

This may be a dupe of #17482, feel free to close out if so.

[andrewrk]

Duplicate of #17482. The fix is cooking: #17503