Fix a number of `run-make` tests on MSVC.

[DiamondLovesYou]

Due to the way MSYS sandboxes file paths, paths passed to cl.exe are expanded into values which are invalid outside of MSYS.

[alexcrichton]

This was done in #28421

[Eh2406]

There is a FIXME related to this issue,
edit: wrong link.
https://github.com/rust-lang/rust/blob/master/src/test/run-make/no-duplicate-libs/Makefile#L4
Now that the issue is closed can the FIXME be fix, or made more specific?