[lld] Support finding pdb files from outputpath (PR #94153)

[via llvm-commits]

GkvJwa wrote:

> You are going to have to add a test for this as well. I think it's fine to always match the behaviour of link.exe for things like this.

Add test(Use the added pdb and obj files to compare before and after)

llvm-pdbutil dump -l t.pdb:

```
before:

                           Lines
============================================================
Mod 0000 | `{{.*}}pdb-from-outputpath-a.obj`:
Mod 0001 | `{{.*}}pdb-from-outputpath-b.obj`:
Mod 0002 | `* Linker *`:

--

after:
                           Lines
============================================================
Mod 0000 | `{{.*}}pdb-from-outputpath-a.obj`:
c:\src\llvm-project\build\a.c (SHA-256: 1112FA2413C56E03F4B5505E57C69AB45D701CFDAB923D4844A7D521FDACD940)
  0001:00000000-0000001B, line/addr entries = 4
     3 00000000      4 00000004      5 0000000C      6 00000016

Mod 0001 | `{{.*}}pdb-from-outputpath-b.obj`:
c:\src\llvm-project\build\b.c (SHA-256: D2547E2F2970ED80738146BB5A4D2B7C45C7BB71B73B541A4162F74A8EDDAF2C)
  0001:00000020-0000002D, line/addr entries = 1
     2 00000020

Mod 0002 | `* Linker *`:
```

https://github.com/llvm/llvm-project/pull/94153