[llvm] [AMDGPU] Don't assume a hazard for empty inline asm (PR #223526)

[via llvm-commits]

xgxanq wrote:

> > Maybe the empty string is a grey area here
> 
> Hmm, my concern is that if we allow poking into inline asm just for an empty string, there will soon be other attempts to look much deeper into it in the future.

That is indeed a valid concern. If other targets extend their own business logic following this pattern, there is little we can do to control that.

https://github.com/llvm/llvm-project/pull/223526