[llvm] [FileCheck] Fix parsing empty global and pseudo variable names (PR #82595)

[Daniil Kovalev via llvm-commits]

kovdan01 wrote:

Thanks @jh7370, forgot to include test cases in the commit initially. See efd7bd8734ee517bf3e7f94bb04fed857c4c0fce for test cases

https://github.com/llvm/llvm-project/pull/82595