Remove checks for ancient gcc/MinGW versions.

Don't test for wxUSE_NORLANDER_HEADERS, this is always true since many, many
years.

Remove tests for gcc version < 3.3, notably 2.95: the minimal supported gcc
version is 3.4.

Closes #15727.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76549 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/gccpriv.h

@@ -65,25 +65,6 @@
     #define wxCHECK_W32API_VERSION( major, minor ) (0)
 #endif
 
-/* Cygwin / Mingw32 with gcc >= 2.95 use new windows headers which
-   are more ms-like (header author is Anders Norlander, hence the name) */
-#if (defined(__MINGW32__) || defined(__CYGWIN__) || defined(__WINE__)) && ((__GNUC__>2) || ((__GNUC__==2) && (__GNUC_MINOR__>=95)))
-    #ifndef wxUSE_NORLANDER_HEADERS
-        #define wxUSE_NORLANDER_HEADERS 1
-    #endif
-#else
-    #ifndef wxUSE_NORLANDER_HEADERS
-        #define wxUSE_NORLANDER_HEADERS 0
-    #endif
-#endif
-
-/* "old" GNUWIN32 is the one without Norlander's headers: it lacks the
-   standard Win32 headers and we define the used stuff ourselves for it
-   in wx/msw/gnuwin32/extra.h */
-#if defined(__GNUC__) && !wxUSE_NORLANDER_HEADERS
-    #define __GNUWIN32_OLD__
-#endif
-
 /* Cygwin 1.0 */
 #if defined(__CYGWIN__) && ((__GNUC__==2) && (__GNUC_MINOR__==9))
     #define __CYGWIN10__