[clang] [llvm] [ARM] Handle roundeven for MVE. (PR #142557)

[David Green via llvm-commits]

================
@@ -424,21 +424,74 @@ entry:
   ret <2 x double> %0
 }
 
-declare <4 x float> @llvm.ceil.v4f32(<4 x float>)
----------------
davemgreen wrote:

Yep - they are not necessary any more for intrinsics, since https://discourse.llvm.org/t/recent-improvements-to-the-ir-parser/77366.

It felt cleaner to remove the definitions, as opposed to add the new roundeven calls or leave them inconsistent.

https://github.com/llvm/llvm-project/pull/142557