[clang] [clang] Robustify openmp test (PR #69739)

[Johannes Doerfert via cfe-commits]

https://github.com/jdoerfert commented:

Your motivation is sound, apologies for the churn this caused.

Thaat said, this alias is not `noalias` but global symbols aliases.
The commit that introduced the NOT check removed:
```
// CHECK-DAG: @_ZN16SpecSpecialFuncs6MethodEv = {{.*}}alias i32 (%struct.SpecSpecialFuncs*), i32 (%struct.SpecSpecialFuncs*)* @_ZN16SpecSpecialFuncs7method_Ev
// CHECK-DAG: @_ZN16SpecSpecialFuncs6methodEv = linkonce_odr {{.*}}alias i32 (%struct.SpecSpecialFuncs*), i32 (%struct.SpecSpecialFuncs*)* @_ZN16SpecSpecialFuncs7method_Ev
```
So we want to avoid `@ ... = ... alias` or similar.


https://github.com/llvm/llvm-project/pull/69739