[clang] [llvm] Adding splitdouble HLSL function (PR #109331)

[Farzon Lotfi via cfe-commits]

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@@ -489,6 +542,9 @@ class OpLowerer {
       case Intrinsic::dx_typedBufferStore:
         HasErrors |= lowerTypedBufferStore(F);
         break;
+      case Intrinsic::dx_splitdouble:
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farzonl wrote:

I'd like to see all the changes to `DXILOpLowering.cpp` removed. I don't see why this can't all be done in cgbuiltins.

https://github.com/llvm/llvm-project/pull/109331