[clang] [llvm] [HLSL] Move length support out of the DirectX Backend (PR #121611)

[Justin Bogner via llvm-commits]

================
@@ -13,6 +13,14 @@ namespace hlsl {
 
 namespace __detail {
 
+template <typename T, typename U> struct is_same {
+  static const bool value = false;
+};
+
+template <typename T> struct is_same<T, T> {
+  static const bool value = true;
+};
----------------
bogner wrote:

These seem fine, but we should make sure we're being aware of how much of standard C++ we're reimplementing in this header as we do more of this stuff.

https://github.com/llvm/llvm-project/pull/121611