A couple of msvc compile fixes from the ml; I haven't tested with msvc, 
but the fixes are reasonable.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@47224 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/ASTConsumers.h b/Driver/ASTConsumers.h
index 08d2268..1ea8b14 100644
--- a/Driver/ASTConsumers.h
+++ b/Driver/ASTConsumers.h
@@ -14,6 +14,7 @@
 #ifndef DRIVER_ASTCONSUMERS_H
 #define DRIVER_ASTCONSUMERS_H
 
+#include <string>
 #include <iosfwd>
 
 namespace llvm {