[clang] Fix CIR_GlobalOp global_visibility assembly format and add tests (PR #190195)

[Andy Kaylor via cfe-commits]

https://github.com/andykaylor commented:

I'm confused. Isn't this the same issue you fixed with https://github.com/llvm/llvm-project/pull/189673? And this PR seems to be deleting `sym_visibility` from the assembly format.

https://github.com/llvm/llvm-project/pull/190195