[llvm] [ARM64EC] Fix thunks for vector args (PR #96003)

[Daniel Paoliello via llvm-commits]

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@@ -414,8 +416,7 @@ Function *AArch64Arm64ECCallLowering::buildExitThunk(FunctionType *FT,
     // with an attribute.)
     //
     // The first argument is the called function, stored in x9.
-    if (Arg.getType()->isArrayTy() || Arg.getType()->isStructTy() ||
-        DL.getTypeStoreSize(Arg.getType()) > 8) {
+    if (Arg.getType() != X64ArgType) {
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dpaoliello wrote:

I went ahead and did this: my nicer to have all of the logic centralized in a single function.

https://github.com/llvm/llvm-project/pull/96003