Implement -fno-short-wchar

llvm-svn: 202058
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 06eb246..37b351c 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3575,7 +3575,8 @@
 
   // -fshort-wchar default varies depending on platform; only
   // pass if specified.
-  if (Arg *A = Args.getLastArg(options::OPT_fshort_wchar))
+  if (Arg *A = Args.getLastArg(options::OPT_fshort_wchar,
+                               options::OPT_fno_short_wchar))
     A->render(Args, CmdArgs);
 
   // -fno-pascal-strings is default, only pass non-default.