[llvm] [AArch64][LoopVectorize] Use either fixed-width or scalable VF when tail-folding (PR #67543)

[Matthew Devereau via llvm-commits]

================
@@ -0,0 +1,109 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 2
+; RUN: opt -S < %s -passes=loop-vectorize -mtriple aarch64-linux-gnu -mattr=+sve 2>&1 | FileCheck %s
+
+define void @test(ptr nocapture noundef writeonly %dst, i32 noundef %n, i64 noundef %val) local_unnamed_addr #0 {
----------------
MDevereau wrote:

I think the name `test` could be refined to something more specific.

Unless the parameter flags are significant here, you can shorten the function definition to 
`define void @test(ptr %dst, i32 %n, i64 %val) {`

the `#0` attributes aren't defined either so can be dropped

https://github.com/llvm/llvm-project/pull/67543