[clang] [clang] SourceLocIdentKind::Function should not be dependent (PR #94942)

[Qizhi Hu via cfe-commits]

jcsxky wrote:

> because we want to make the name of the function and any template parameter
refers to the instantiated function rather than that of the function template.

Does that mean we should transform the `SourceLocExpr` into a certain function name when instantiating  if it is `__builtin_FUNCTION`? 

https://github.com/llvm/llvm-project/pull/94942