Misc minor fixes for clang for the Windows target.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73050 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/clang-cc/clang-cc.cpp b/tools/clang-cc/clang-cc.cpp
index f38c6bd..c58340c 100644
--- a/tools/clang-cc/clang-cc.cpp
+++ b/tools/clang-cc/clang-cc.cpp
@@ -808,7 +808,8 @@
   
   if (PascalStrings.getPosition())
     Options.PascalStrings = PascalStrings;
-  Options.Microsoft = MSExtensions;
+  if (MSExtensions.getPosition())
+    Options.Microsoft = MSExtensions;
   Options.WritableStrings = WritableStrings;
   if (NoLaxVectorConversions.getPosition())
       Options.LaxVectorConversions = 0;