Adding -nostdinc++ to Android build of Swift.

On Android, we explicitly setup the include paths for the C++ headers.
As a result, we do not want to pick up any system headers that the
toolchain may have visible to it. If this flag is not added then clang
will look in the wrong places to get the headers for things like stddef
etc.

Author: plotfi

cmake/modules/AddSwift.cmake

@@ -324,6 +324,7 @@ function(_add_variant_c_compile_flags)
   endif()
 
   if("${CFLAGS_SDK}" STREQUAL "ANDROID")
+    list(APPEND result -nostdinc++)
     swift_android_libcxx_include_paths(CFLAGS_CXX_INCLUDES)
     swift_android_include_for_arch("${CFLAGS_ARCH}" "${CFLAGS_ARCH}_INCLUDE")
     foreach(path IN LISTS CFLAGS_CXX_INCLUDES ${CFLAGS_ARCH}_INCLUDE)