[clang] [Clang][test] Fix space in ld path (PR #200012)

[Michael Kruse via cfe-commits]

Meinersbur wrote:

> Can you please add a `[/\\]` in front of the ld to ensure that we don't pick up `[^/\\]*ld"` as a match.

I applied that, but note that the other arch's tests don't do that.

https://github.com/llvm/llvm-project/pull/200012