[clang] [clang] Implement the __builtin_type_order intrinsic for P2830R10 Constexpr Type Ordering (PR #216462)

[Yanzuo Liu via cfe-commits]

================
@@ -2886,6 +2886,49 @@ class CXXPseudoDestructorExpr : public Expr {
   }
 };
 
+/// Represents a C++26 __builtin_type_order(T, U) expression. Used to implement
+/// std::type_order.
+class BuiltinTypeOrderExpr final : public Expr {
----------------
zwuis wrote:

We have facilities about binary type traits. You can search for `__is_same` in the codebase for more information. I don't think we need one more class.

https://github.com/llvm/llvm-project/pull/216462