patch 8.2.1422: the Mac GUI implementation is outdated

Problem:    The Mac GUI implementation is outdated and probably doesn't even
            work.
Solution:   Remove the Mac GUI code.  The MacVim project provides the
            supported Vim GUI version.
diff --git a/src/misc2.c b/src/misc2.c
index 3e16c36..0370bdf 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -3341,7 +3341,7 @@
 }
 
 #if defined(FEAT_SESSION) || defined(FEAT_AUTOCHDIR) \
-	|| defined(MSWIN) || defined(FEAT_GUI_MAC) || defined(FEAT_GUI_GTK) \
+	|| defined(MSWIN) || defined(FEAT_GUI_GTK) \
 	|| defined(FEAT_NETBEANS_INTG) \
 	|| defined(PROTO)
 /*