patch 7.4.1364
Problem:    The Win 16 code is not maintained and unused.
Solution:   Remove the Win 16 support.
diff --git a/src/vim.h b/src/vim.h
index 52eebab..97155d2 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -27,7 +27,7 @@
 # endif
 #endif
 
-#if defined(MSDOS) || defined(WIN16) || defined(WIN32) || defined(_WIN64) \
+#if defined(MSDOS) || defined(WIN32) || defined(_WIN64) \
 	|| defined(__EMX__)
 # include "vimio.h"
 #endif
@@ -150,7 +150,7 @@
 #if defined(FEAT_GUI_W32) || defined(FEAT_GUI_W16)
 # define FEAT_GUI_MSWIN
 #endif
-#if defined(WIN16) || defined(WIN32) || defined(_WIN64)
+#if defined(WIN32) || defined(_WIN64)
 # define MSWIN
 #endif
 /* Practically everything is common to both Win32 and Win64 */
@@ -308,10 +308,6 @@
 # include "os_msdos.h"
 #endif
 
-#ifdef WIN16
-# include "os_win16.h"
-#endif
-
 #ifdef WIN3264
 # include "os_win32.h"
 #endif
@@ -471,7 +467,7 @@
 # include <sys/stat.h>
 #endif
 
-#if defined(HAVE_ERRNO_H) || defined(DJGPP) || defined(WIN16) \
+#if defined(HAVE_ERRNO_H) || defined(DJGPP) \
 	|| defined(WIN32) || defined(_WIN64) || defined(__EMX__)
 # include <errno.h>
 #endif