[clang] [clang][driver] Fix unused argument warning for `/std:c++20` for precompiled module inputs to `clang-cl` (PR #99300)

[Sharadh Rajaraman via cfe-commits]

https://github.com/sharadhr created https://github.com/llvm/llvm-project/pull/99300

Relates to #98761: `-fmodule-file` requires `/std:c++20` or greater, but passing that option results in an unused argument warning. This resolves that.

>From 11aaae5439b33ac636e8580b96d16b6d0d9dbd0a Mon Sep 17 00:00:00 2001
From: Sharadh Rajaraman <r.sharadh at outlook.sg>
Date: Sun, 14 Jul 2024 11:05:57 +0100
Subject: [PATCH 1/2] `TY_ModuleFile` should be a 'CXX' file type

---
 clang/lib/Driver/Types.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/lib/Driver/Types.cpp b/clang/lib/Driver/Types.cpp
index a7b6b9000e1d2..c6a03f4491dd7 100644
--- a/clang/lib/Driver/Types.cpp
+++ b/clang/lib/Driver/Types.cpp
@@ -242,7 +242,7 @@ bool types::isCXX(ID Id) {
   case TY_CXXHUHeader:
   case TY_PP_CXXHeaderUnit:
   case TY_ObjCXXHeader: case TY_PP_ObjCXXHeader:
-  case TY_CXXModule: case TY_PP_CXXModule:
+  case TY_CXXModule: case TY_PP_CXXModule: case TY_ModuleFile:
   case TY_PP_CLCXX:
   case TY_CUDA: case TY_PP_CUDA: case TY_CUDA_DEVICE:
   case TY_HIP:

>From fe0e22ae80572f8b084b94c80c8f27098b74d1a3 Mon Sep 17 00:00:00 2001
From: Sharadh Rajaraman <3754080+sharadhr at users.noreply.github.com>
Date: Tue, 16 Jul 2024 20:10:12 +0100
Subject: [PATCH 2/2] Resolve `clang-format` issues

---
 clang/lib/Driver/Types.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/clang/lib/Driver/Types.cpp b/clang/lib/Driver/Types.cpp
index c6a03f4491dd7..842eb59b7382d 100644
--- a/clang/lib/Driver/Types.cpp
+++ b/clang/lib/Driver/Types.cpp
@@ -242,7 +242,9 @@ bool types::isCXX(ID Id) {
   case TY_CXXHUHeader:
   case TY_PP_CXXHeaderUnit:
   case TY_ObjCXXHeader: case TY_PP_ObjCXXHeader:
-  case TY_CXXModule: case TY_PP_CXXModule: case TY_ModuleFile:
+  case TY_CXXModule: 
+  case TY_PP_CXXModule:
+  case TY_ModuleFile:
   case TY_PP_CLCXX:
   case TY_CUDA: case TY_PP_CUDA: case TY_CUDA_DEVICE:
   case TY_HIP: