patch 8.1.1915: more functions can be used as methods

Problem:    More functions can be used as methods.
Solution:   Make various functions usable as a method.

runtime/doc/eval.txt

@@ -3410,6 +3410,9 @@ char2nr({expr} [, {utf8}])					*char2nr()*
 		    let list = map(split(str, '\zs'), {_, val -> char2nr(val)})
 <		Result: [65, 66, 67]
 
+		Can also be used as a |method|: >
+			GetChar()->char2nr()
+
 chdir({dir})						*chdir()*
 		Change the current working directory to {dir}.  The scope of
 		the directory change depends on the directory of the current
@@ -3430,6 +3433,9 @@ chdir({dir})						*chdir()*
 			   " ... do some work
 			   call chdir(save_dir)
 			endif
+
+<		Can also be used as a |method|: >
+			GetDir()->chdir()
 <
 cindent({lnum})						*cindent()*
 		Get the amount of indent for line {lnum} according the C
@@ -3440,12 +3446,18 @@ cindent({lnum})						*cindent()*
 		feature, -1 is returned.
 		See |C-indenting|.
 
+		Can also be used as a |method|: >
+			GetLnum()->cindent()
+
 clearmatches([{win}])					*clearmatches()*
 		Clears all matches previously defined for the current window
 		by |matchadd()| and the |:match| commands.
 		If {win} is specified, use the window with this number or
 		window ID instead of the current window.
 
+		Can also be used as a |method|: >
+			GetWin()->clearmatches()
+<
 							*col()*
 col({expr})	The result is a Number, which is the byte index of the column
 		position given with {expr}.  The accepted positions are:
@@ -3481,6 +3493,9 @@ col({expr})	The result is a Number, which is the byte index of the column
 				\<C-O>:set ve=all<CR>
 				\<C-O>:echo col(".") . "\n" <Bar>
 				\let &ve = save_ve<CR>
+
+<		Can also be used as a |method|: >
+			GetPos()->col()
 <
 
 complete({startcol}, {matches})			*complete()* *E785*
@@ -3512,6 +3527,10 @@ complete({startcol}, {matches})			*complete()* *E785*
 <		This isn't very useful, but it shows how it works.  Note that
 		an empty string is returned to avoid a zero being inserted.
 
+		Can also be used as a |method|, the second argument is passed
+		in: >
+			GetMatches()->complete(col('.'))
+
 complete_add({expr})				*complete_add()*
 		Add {expr} to the list of matches.  Only to be used by the
 		function specified with the 'completefunc' option.
@@ -3521,6 +3540,9 @@ complete_add({expr})				*complete_add()*
 		See |complete-functions| for an explanation of {expr}.  It is
 		the same as one item in the list that 'omnifunc' would return.
 
+		Can also be used as a |method|: >
+			GetMoreMatches()->complete_add()
+
 complete_check()				*complete_check()*
 		Check for a key typed while looking for completion matches.
 		This is to be used when looking for matches takes some time.
@@ -3581,6 +3603,9 @@ complete_info([{what}])
 			call complete_info(['mode'])
 			" Get only 'mode' and 'pum_visible'
 			call complete_info(['mode', 'pum_visible'])
+
+<		Can also be used as a |method|: >
+			GetItems()->complete_info()
 <
 						*confirm()*
 confirm({msg} [, {choices} [, {default} [, {type}]]])
@@ -3636,6 +3661,9 @@ confirm({msg} [, {choices} [, {default} [, {type}]]])
 		don't fit, a vertical layout is used anyway.  For some systems
 		the horizontal layout is always used.
 
+		Can also be used as a |method|in: >
+			BuildMessage()->confirm("&Yes\n&No")
+
 							*copy()*
 copy({expr})	Make a copy of {expr}.  For Numbers and Strings this isn't
 		different from using {expr} directly.
@@ -3765,12 +3793,18 @@ cursor({list})
 		position within a <Tab> or after the last character.
 		Returns 0 when the position could be set, -1 otherwise.
 
+		Can also be used as a |method|: >
+			GetCursorPos()->cursor()
+
 debugbreak({pid})					*debugbreak()*
 		Specifically used to interrupt a program being debugged.  It
 		will cause process {pid} to get a SIGTRAP.  Behavior for other
 		processes is undefined. See |terminal-debugger|.
 		{only available on MS-Windows}
 
+		Can also be used as a |method|: >
+			GetPid()->debugbreak()
+
 deepcopy({expr} [, {noref}])				*deepcopy()* *E698*
 		Make a copy of {expr}.  For Numbers and Strings this isn't
 		different from using {expr} directly.
@@ -3792,6 +3826,9 @@ deepcopy({expr} [, {noref}])				*deepcopy()* *E698*
 		{noref} set to 1 will fail.
 		Also see |copy()|.
 
+		Can also be used as a |method|: >
+			GetObject()->deepcopy()
+
 delete({fname} [, {flags}])					*delete()*
 		Without {flags} or with {flags} empty: Deletes the file by the
 		name {fname}.  This also works when {fname} is a symbolic link.
@@ -3813,6 +3850,9 @@ delete({fname} [, {flags}])					*delete()*
 		To delete a line from the buffer use |:delete| or
 		|deletebufline()|.
 
+		Can also be used as a |method|: >
+			GetName()->delete()
+
 deletebufline({expr}, {first} [, {last}])		*deletebufline()*
 		Delete lines {first} to {last} (inclusive) from buffer {expr}.
 		If {last} is omitted then delete line {first} only.
@@ -3824,6 +3864,9 @@ deletebufline({expr}, {first} [, {last}])		*deletebufline()*
 		when using |line()| this refers to the current buffer. Use "$"
 		to refer to the last line in buffer {expr}.
 
+		Can also be used as a |method|: >
+			GetBuffer()->deletebufline(1)
+
 							*did_filetype()*
 did_filetype()	Returns |TRUE| when autocommands are being executed and the
 		FileType event has been triggered at least once.  Can be used
@@ -3845,6 +3888,9 @@ diff_filler({lnum})					*diff_filler()*
 		line, "'m" mark m, etc.
 		Returns 0 if the current window is not in diff mode.
 
+		Can also be used as a |method|: >
+			GetLnum()->diff_filler()
+
 diff_hlID({lnum}, {col})				*diff_hlID()*
 		Returns the highlight ID for diff mode at line {lnum} column
 		{col} (byte index).  When the current line does not have a
@@ -3856,6 +3902,8 @@ diff_hlID({lnum}, {col})				*diff_hlID()*
 		The highlight ID can be used with |synIDattr()| to obtain
 		syntax information about the highlighting.
 
+		Can also be used as a |method|: >
+			GetLnum()->diff_hlID(col)
 environ()						*environ()*
 		Return all of environment variables as dictionary. You can
 		check if an environment variable exists like this: >