Undef'ing _WIN32_IE to silence an MSVC warning about redefining a macro value.

No functional change intended.

llvm-svn: 200704
diff --git a/llvm/lib/Support/Windows/Windows.h b/llvm/lib/Support/Windows/Windows.h
index 1f3417d..5666de2 100644
--- a/llvm/lib/Support/Windows/Windows.h
+++ b/llvm/lib/Support/Windows/Windows.h
@@ -18,6 +18,7 @@
 
 // mingw-w64 tends to define it as 0x0502 in its headers.
 #undef _WIN32_WINNT
+#undef _WIN32_IE
 
 // Require at least Windows XP(5.1) API.
 #define _WIN32_WINNT 0x0501