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

[Jan Patrick Lehr via llvm-commits]

jplehr wrote:

It seems this broke a couple of bots
https://lab.llvm.org/staging/#/builders/105/builds/5334
https://lab.llvm.org/buildbot/#/builders/30/builds/6885

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