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

[Joseph Huber 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"];
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jhuber6 wrote:

On second thought, I decided to leave it because it both matches the LLVM intrinsic of the same name and because none of the other vector based builtins use 'vector' in the name (like __builtin_reduce_add) and it would stand out..

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