[llvm] [llvm][unittests] Put human-readable names on TargetParserTests. NFC (PR #80749)

[Francesco Petrogalli via llvm-commits]

fpetrogalli wrote:

It is not clear to me how this change makes the output human-readable. Can you please describe in the commit message how the before/after of the output? 

https://github.com/llvm/llvm-project/pull/80749