[clang] [Clang] Add builtins for masked vector loads / stores (PR #154464)

[Timm Baeder via cfe-commits]

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@@ -1232,6 +1232,18 @@ def ConvertVector : Builtin {
   let Prototype = "void(...)";
 }
 
+def MaskedLoad : Builtin {
+  let Spellings = ["__builtin_masked_load"];
+  let Attributes = [NoThrow, Const, CustomTypeChecking, Constexpr];
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tbaederr wrote:

There's no constexpr implementation here.

https://github.com/llvm/llvm-project/pull/154464