[Driver] -nostdinc -nostdinc++: don't warn for -Wunused-command-line-argument

Author: MaskRay

clang/lib/Driver/ToolChains/Gnu.cpp

@@ -2882,9 +2882,8 @@ void Generic_GCC::AddMultilibIncludeArgs(const ArgList &DriverArgs,
 
 void Generic_GCC::AddClangCXXStdlibIncludeArgs(const ArgList &DriverArgs,
                                                ArgStringList &CC1Args) const {
-  if (DriverArgs.hasArg(options::OPT_nostdinc) ||
-      DriverArgs.hasArg(options::OPT_nostdincxx) ||
-      DriverArgs.hasArg(options::OPT_nostdlibinc))
+  if (DriverArgs.hasArg(options::OPT_nostdinc, options::OPT_nostdincxx,
+                        options::OPT_nostdlibinc))
     return;
 
   switch (GetCXXStdlibType(DriverArgs)) {

clang/test/Driver/nostdincxx.cpp

@@ -1,6 +1,7 @@
 // RUN: not %clangxx -nostdinc %s 2>&1 | FileCheck %s
 // RUN: not %clangxx -nostdinc++ %s 2>&1 | FileCheck %s
 // RUN: not %clangxx -nostdlibinc %s 2>&1 | FileCheck %s
+// RUN: not %clangxx -fsyntax-only -nostdinc -nostdinc++ %s 2>&1 | FileCheck /dev/null --implicit-check-not=-Wunused-command-line-argument
 // CHECK: file not found
 #include <vector>