Remove (Open)Watcom support.

This compiler is not being developed since several years and almost certainly
can't be used to build the current wxWidgets sources anyhow, so remove all
support for it, including a lot of extremely ugly workarounds for its bugs
with template functions.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76546 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/platform.h

@@ -292,12 +292,8 @@
 #    ifndef __DOS__
 #        define __DOS__
 #    endif
-    /* size_t is the same as unsigned int for Watcom 11 compiler, */
-    /* so define it if it hadn't been done by configure yet */
+    /* define it if it hadn't been done by configure yet */
 #    if !defined(wxSIZE_T_IS_UINT) && !defined(wxSIZE_T_IS_ULONG)
-#        ifdef __WATCOMC__
-#            define wxSIZE_T_IS_UINT
-#        endif
 #        ifdef __DJGPP__
 #            define wxSIZE_T_IS_ULONG
 #        endif
@@ -421,8 +417,7 @@
     _UNICODE macros as it includes _mingw.h which relies on them being set.
  */
 #if ( defined( __GNUWIN32__ ) || defined( __MINGW32__ ) || \
-    ( defined( __CYGWIN__ ) && defined( __WINDOWS__ ) ) || \
-      wxCHECK_WATCOM_VERSION(1,0) ) && \
+    ( defined( __CYGWIN__ ) && defined( __WINDOWS__ ) ) ) && \
     !defined(__DOS__) && \
     !defined(__WXMOTIF__) && \
     !defined(__WXX11__)
@@ -576,7 +571,7 @@
 #if defined(_MSC_VER) && (_MSC_VER >= 1310)
 #    undef wxUSE_IOSTREAMH
 #    define wxUSE_IOSTREAMH 0
-#elif defined(__DMC__) || defined(__WATCOMC__)
+#elif defined(__DMC__)
 #    undef wxUSE_IOSTREAMH
 #    define wxUSE_IOSTREAMH 1
 #elif defined(__MINGW32__)