[clang] [AMDGPU] Allow overload of __builtin_amdgcn_mov/update_dpp (PR #112447)

[Matt Arsenault via cfe-commits]

arsenm wrote:

> I actually wish a better way to have overloaded builtins in clang. I do not believe any user of these builtins is expecting that a wide integer will be silently truncated, and any fp will go through fptosi and backwards after, like we do now. 

Yes, C was a mistake 

https://github.com/llvm/llvm-project/pull/112447