[clang] Hlsl dst function (PR #133828)

[Damyan Pepper via cfe-commits]

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@@ -35,6 +35,12 @@ length_vec_impl(vector<T, N> X) {
 #endif
 }
 
+template <typename T>
+constexpr vector<T, 4> dst_impl(vector<T, 4> src0, vector<T, 4> src1) {
+  vector<T, 4> dest = {1, src0[1] * src1[1], src0[2], src1[3]};
+  return dest;
+}
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damyanp wrote:

Coding conventions:

```suggestion
constexpr vector<T, 4> dst_impl(vector<T, 4> Src0, vector<T, 4> Src1) {
  vector<T, 4> Dest = {1, Src0[1] * Src1[1], Src0[2], Src1[3]};
  return Dest;
}
```

https://github.com/llvm/llvm-project/pull/133828