[llvm] [AMDGPU] Assert no bad shift operations will happen (PR #108416)

[Georgi Mirazchiyski via llvm-commits]

GeorgeWeb wrote:

Not aware how assigning reviewers works and I wanted to see your opinion on this @arsenm. Thanks!

Potential "bad bit-shift opertations" was flagged by a static analyser and I've come to the conclusion that no bad shifts can actually happen but I am not sure my understanding is complete here.

https://github.com/llvm/llvm-project/pull/108416