[llvm] [AArch64][MC]Add diagnostic message for Multiple of 2/4 for ZPR128 (PR #90600)

[Maciej Gabka via llvm-commits]

================
@@ -25,3 +25,13 @@ luti4   {z0.b - z12.b}, zt0, {z0-z1}
 // CHECK: [[@LINE-1]]:{{[0-9]+}}: error: invalid number of vectors
 // CHECK-NEXT: luti4   {z0.b - z12.b}, zt0, {z0-z1}
 // CHECK-NOT: [[@LINE-1]]:{{[0-9]+}}:
+
----------------
mgabka wrote:

looks to me like adding a test for zip, inside this file breaks the convention, as zip is just part of SME2, so probably should be inside SME2 directory and use appropriate -mattr values

https://github.com/llvm/llvm-project/pull/90600