lib/Support/Windows/Windows.h: Update required IE ver. 0x0600 should be enough for Windows XP.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138319 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Windows/Windows.h b/lib/Support/Windows/Windows.h
index a6a425f..67b6f01 100644
--- a/lib/Support/Windows/Windows.h
+++ b/lib/Support/Windows/Windows.h
@@ -21,7 +21,7 @@
 
 // Require at least Windows XP(5.1) API.
 #define _WIN32_WINNT 0x0501
-#define _WIN32_IE    0x0500 // MinGW at it again.
+#define _WIN32_IE    0x0600 // MinGW at it again.
 #define WIN32_LEAN_AND_MEAN
 
 #include "llvm/Config/config.h" // Get build system configuration settings