Fix wx headers compilation in mingw32 strict ANSI mode.

Add checks for !defined(__STRICT_ANSI__) when checking for various common but
non-standard CRT extensions.

This allows compiling programs using wx with g++ -std=c++[0x] option (notice
that compiling wx itself using it still doesn't work).

Closes #11374.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@62518 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/filefn.h

@@ -344,7 +344,7 @@ enum wxFileKind
 
     // finally the default char-type versions
     #if wxUSE_UNICODE
-        #if wxUSE_UNICODE_MSLU
+        #if wxUSE_UNICODE_MSLU || defined(__STRICT_ANSI__)
             // implement the missing file functions in Win9x ourselves
             WXDLLIMPEXP_BASE int wxMSLU__wopen(const wxChar *name,
                                                int flags, int mode);