[clang] [llvm] [CodeGen][LLVM] Make the `va_list` related intrinsics generic. (PR #85460)

[Matt Arsenault via cfe-commits]

================
@@ -700,10 +700,13 @@ class MSBuiltin<string name> {
 //===--------------- Variable Argument Handling Intrinsics ----------------===//
 //
 
-def int_vastart : DefaultAttrsIntrinsic<[], [llvm_ptr_ty], [], "llvm.va_start">;
-def int_vacopy  : DefaultAttrsIntrinsic<[], [llvm_ptr_ty, llvm_ptr_ty], [],
-                            "llvm.va_copy">;
-def int_vaend   : DefaultAttrsIntrinsic<[], [llvm_ptr_ty], [], "llvm.va_end">;
+def int_vastart : DefaultAttrsIntrinsic<[],
+                                        [llvm_anyptr_ty], [], "llvm.va_start">;
+def int_vacopy  : DefaultAttrsIntrinsic<[],
+                                        [llvm_anyptr_ty, llvm_anyptr_ty], [],
+                                        "llvm.va_copy">;
----------------
arsenm wrote:

vacopy probably shouldn't have 2 type parameters. 
```suggestion
def int_vacopy  : DefaultAttrsIntrinsic<[],
                                        [llvm_anyptr_ty, LLVMMatchType<0>], [],
                                        "llvm.va_copy">;
```

https://github.com/llvm/llvm-project/pull/85460