[llvm] [AMDGPU] Skip non-first terminators when forcing emit zero flag (PR #112116)

[Jay Foad via llvm-commits]

jayfoad wrote:

Why do you say "**non-first** terminators" in the description?

In the test case, why does SIInsertWaitcnts want to put a wait between the two branch instructions?

https://github.com/llvm/llvm-project/pull/112116