patch 8.1.0226: too many #ifdefs

Problem:    Too many #ifdefs.
Solution:   Graduate the +vreplace feature, it's not much code and quite a few
            #ifdefs.
diff --git a/src/vim.h b/src/vim.h
index fb476c5..a85d47f 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -675,10 +675,8 @@
 
 #define REPLACE_FLAG	0x40	/* Replace mode flag */
 #define REPLACE		(REPLACE_FLAG + INSERT)
-#ifdef FEAT_VREPLACE
-# define VREPLACE_FLAG	0x80	/* Virtual-replace mode flag */
-# define VREPLACE	(REPLACE_FLAG + VREPLACE_FLAG + INSERT)
-#endif
+#define VREPLACE_FLAG	0x80	/* Virtual-replace mode flag */
+#define VREPLACE	(REPLACE_FLAG + VREPLACE_FLAG + INSERT)
 #define LREPLACE	(REPLACE_FLAG + LANGMAP)
 
 #define NORMAL_BUSY	(0x100 + NORMAL) /* Normal mode, busy with a command */