[llvm] [InstCombine] Pick bfloat over half when shrinking ops that started with an fpext from bfloat (PR #82493)

[Nikita Popov via llvm-commits]

================
@@ -437,3 +437,14 @@ define half @bf16_to_f32_to_f16(bfloat %a) nounwind {
   %z = fptrunc float %y to half
   ret half %z
 }
+
+define bfloat @bf16_frem(bfloat %x) nounwind {
----------------
nikic wrote:

Drop nounwind

https://github.com/llvm/llvm-project/pull/82493