[clang] [Clang][SME2] Add multi-vector add/sub builtins (PR #69725)

[Kerry McLaughlin via cfe-commits]

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@@ -257,7 +257,7 @@ class ImmCheck<int arg, ImmCheckType kind, int eltSizeArg = -1> {
 }
 
 class Inst<string n, string p, string t, MergeType mt, string i,
-           list<FlagType> ft, list<ImmCheck> ch, MemEltType met> {
+           list<FlagType> ft, list<ImmCheck> ch, MemEltType met = MemEltTyDefault> {
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kmclaughlin-arm wrote:

Hi @dtemirbulatov, this change is just to set the default MemEltType to MemEltTyDefault, so that we don't have to provide this in every builtin definition. 

https://github.com/llvm/llvm-project/pull/69725