[clang] [llvm] [HLSL][DXIL] Implement `refract` intrinsic (PR #136026)

[Kaitlin Peng via cfe-commits]

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@@ -71,6 +71,27 @@ constexpr vector<T, L> reflect_vec_impl(vector<T, L> I, vector<T, L> N) {
 #endif
 }
 
+template <typename T> constexpr T refract_impl(T I, T N, T eta) {
+  T k = 1 - eta * eta * (1 - (N * I * N *I));
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kmpeng wrote:

Variables should [start with an upper-case letter](https://llvm.org/docs/CodingStandards.html#name-types-functions-variables-and-enumerators-properly) (i.e. K, Eta). Should be upper-case in the other files too.

https://github.com/llvm/llvm-project/pull/136026