-Werror,-Wignored-attributes

(__declspec attribute 'allocator' in MSVC 2015 atlalloc.h; clang-cl)

Change-Id: I88d2bc4667ded75a545c95f428e654be787b03f8

extensions/source/ole/windata.hxx

@@ -29,6 +29,7 @@
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wall"
 #pragma clang diagnostic ignored "-Wextra"
+#pragma clang diagnostic ignored "-Wignored-attributes"
 #pragma clang diagnostic ignored "-Wint-to-pointer-cast"
 #pragma clang diagnostic ignored "-Winvalid-noreturn"
 #pragma clang diagnostic ignored "-Wmicrosoft"