Unbreak mingw build


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@45328 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Driver/RewriteTest.cpp b/Driver/RewriteTest.cpp
index c9dd0f7..4cb0dce 100644
--- a/Driver/RewriteTest.cpp
+++ b/Driver/RewriteTest.cpp
@@ -21,6 +21,7 @@
 #include "clang/Lex/Lexer.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Config/alloca.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <sstream>
 using namespace clang;