patch 8.0.0241: fallback implementation of mch_memmove is unused

Problem:    Vim defines a mch_memmove() function but it doesn't work, thus is
            always unused.
Solution:   Remove the mch_memmove implementation. (suggested by Dominique
            Pelle)

src/misc2.c

@@ -1740,34 +1740,6 @@ vim_memset(void *ptr, int c, size_t size)
 }
 #endif
 
-/* skipped when generating prototypes, the prototype is in vim.h */
-#ifdef VIM_MEMMOVE
-/*
- * Version of memmove() that handles overlapping source and destination.
- * For systems that don't have a function that is guaranteed to do that (SYSV).
- */
-    void
-mch_memmove(void *src_arg, void *dst_arg, size_t len)
-{
-    /*
-     * A void doesn't have a size, we use char pointers.
-     */
-    char *dst = dst_arg, *src = src_arg;
-
-					/* overlap, copy backwards */
-    if (dst > src && dst < src + len)
-    {
-	src += len;
-	dst += len;
-	while (len-- > 0)
-	    *--dst = *--src;
-    }
-    else				/* copy forwards */
-	while (len-- > 0)
-	    *dst++ = *src++;
-}
-#endif
-
 #if (!defined(HAVE_STRCASECMP) && !defined(HAVE_STRICMP)) || defined(PROTO)
 /*
  * Compare two strings, ignoring case, using current locale.

src/os_unix.h

@@ -423,21 +423,17 @@ typedef struct dsc$descriptor   DESC;
 # endif
 #endif
 
-/* memmove is not present on all systems, use memmove, bcopy, memcpy or our
- * own version */
-/* Some systems have (void *) arguments, some (char *). If we use (char *) it
+/* memmove() is not present on all systems, use memmove, bcopy or memcpy.
+ * Some systems have (void *) arguments, some (char *). If we use (char *) it
  * works for all */
-#ifdef USEMEMMOVE
+#if defined(USEMEMMOVE) || (!defined(USEBCOPY) && !defined(USEMEMCPY))
 # define mch_memmove(to, from, len) memmove((char *)(to), (char *)(from), len)
 #else
 # ifdef USEBCOPY
 #  define mch_memmove(to, from, len) bcopy((char *)(from), (char *)(to), len)
 # else
-#  ifdef USEMEMCPY
+    /* ifdef USEMEMCPY */
 #   define mch_memmove(to, from, len) memcpy((char *)(to), (char *)(from), len)
-#  else
-#   define VIM_MEMMOVE	    /* found in misc2.c */
-#  endif
 # endif
 #endif
 

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    241,
 /**/
     240,
 /**/

src/vim.h

@@ -1714,15 +1714,8 @@ typedef unsigned short disptick_T;	/* display tick type */
 
 typedef void	    *vim_acl_T;		/* dummy to pass an ACL to a function */
 
-/*
- * Include a prototype for mch_memmove(), it may not be in alloc.pro.
- */
-#ifdef VIM_MEMMOVE
-void mch_memmove(void *, void *, size_t);
-#else
-# ifndef mch_memmove
-#  define mch_memmove(to, from, len) memmove(to, from, len)
-# endif
+#ifndef mch_memmove
+# define mch_memmove(to, from, len) memmove((char*)(to), (char*)(from), (char*)(len))
 #endif
 
 /*