[llvm] [InstCombine] Limit canonicalization of extractelement(cast) to constant index or same basic block. (PR #166227)

[via llvm-commits]

================
@@ -40,19 +40,50 @@ define i32 @test_bitcast(i32 %i) {
 
 declare void @use(i32)
 
+define void @test_poison_branch(<4 x float> %in, i32 %a, i1 %cond) {
----------------
azwolski wrote:

This is a leftover, thanks 

https://github.com/llvm/llvm-project/pull/166227