Unbreak VC++ build.

llvm-svn: 31464
diff --git a/llvm/win32/config.h b/llvm/win32/config.h
index 05ee990..5783636 100644
--- a/llvm/win32/config.h
+++ b/llvm/win32/config.h
@@ -20,3 +20,5 @@
 #define LTDL_SHLIB_EXT ".dll" 
 #define LTDL_SYSSEARCHPATH "" 
 #define LLVM_ON_WIN32 1 
+
+#define strtoll strtol