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.

runtime/doc/change.txt

@@ -177,8 +177,6 @@ gR			Enter Virtual Replace mode: Each character you type
 			<Tab> may replace several characters at once.
 			Repeat the entered text [count]-1 times.  See
 			|Virtual-Replace-mode| for more details.
-			{not available when compiled without the |+vreplace|
-			feature}
 
 							*c*
 ["x]c{motion}		Delete {motion} text [into register x] and start
@@ -303,8 +301,6 @@ gr{char}		Replace the virtual characters under the cursor with
 			space.  See |gR| and |Virtual-Replace-mode| for more
 			details.  As with |r| a count may be given.
 			{char} can be entered like with |r|.
-			{not available when compiled without the |+vreplace|
-			feature}
 
 						*digraph-arg*
 The argument for Normal mode commands like |r| and |t| is a single character.

runtime/doc/various.txt

@@ -461,7 +461,7 @@ N  *+viminfo*		|'viminfo'|
 N  *+virtualedit*	|'virtualedit'|
 S  *+visual*		Visual mode |Visual-mode| Always enabled since 7.4.200.
 N  *+visualextra*	extra Visual mode commands |blockwise-operators|
-N  *+vreplace*		|gR| and |gr|
+T  *+vreplace*		|gR| and |gr|
    *+vtp*		on MS-Windows console: support for 'termguicolors'
 N  *+wildignore*	|'wildignore'|
 N  *+wildmenu*		|'wildmenu'|