[Clang][test] Fix space in ld path (#200012)
The driver resolves the path to the linker ("ld") to the absolute path.
Microsoft Visual Studio comes with its own instance of `ld.lld` which it
installs under
"c:\\program files\\microsoft visual studio\\2022\\community\\vc\\tools\\llvm\\x64\\bin\\ld.lld.exe"
In the developer command prompt, this path is added to PATH where the
Clang driver finds it. However, this path does not match regular
expression `"{{[^" ]*}}ld{{[^" ]*}}"` used by the MIPS test because the
path contains spaces.
Fix the test failure by matching only the the trailing component after
`ld`. Matching the prefix of the path is unique to the MIPS test, this
is not done with tests for other platforms.
