Fix MSVC build.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@143770 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 9e34b02..8083fe0 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -44,7 +44,9 @@
 // environment.
 #ifdef _MSC_VER
   #define WIN32_LEAN_AND_MEAN 1
-  #include <windows.h>
+  #include <Windows.h>
+  #undef min
+  #undef max
 #endif
 
 using namespace clang::driver;
@@ -2182,7 +2184,7 @@
     path = vsIDEInstallDir;
     return true;
   }
-  
+
   if (hasVCExpressDir && vsExpressIDEInstallDir[0]) {
     char *p = (char*)strstr(vsExpressIDEInstallDir, "\\Common7\\IDE");
     if (p)