[clang] [clang][sema] consolidate diags for incompatible_vector_* (PR #83609)

[Farzon Lotfi via cfe-commits]

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@@ -5241,8 +5241,8 @@ bool CheckVectorElementCallArgs(Sema *S, CallExpr *TheCall) {
 
   // Note: if we get here one of the args is a scalar which
   // requires a VectorSplat on Arg0 or Arg1
-  S->Diag(BuiltinLoc, diag::err_vec_builtin_non_vector_all)
-      << TheCall->getDirectCallee()
+  S->Diag(BuiltinLoc, diag::err_vec_builtin_non_vector)
+      << TheCall->getDirectCallee() << /*all args*/ true
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farzonl wrote:

Originally this bool was determined by `(TheCall->getNumArgs() != 2)` Chris preferred the `all` language. So the comment here is to indicate that we are always going to go with all even when arg count is 2. I didn't want to use the same comment because  a future editor might think there is a bug here. 

https://github.com/llvm/llvm-project/pull/83609