vim-patch:8.2.0578: heredoc for interfaces does not support "trim"

Problem:    Heredoc for interfaces does not support "trim".
Solution:   Update the script heredoc support to be same as the :let command.
            (Yegappan Lakshmanan, closes vim/vim#5916)

https://github.com/vim/vim/commit/6c2b7b8055b96463f78abb70f58c4c6d6d4b9d55

4 files changed, 14 insertions, 15 deletions

diff --git a/runtime/doc/if_perl.txt b/runtime/doc/if_perl.txt
index e4ec6dcf45..c3b49dc5bb 100644
--- a/runtime/doc/if_perl.txt
+++ b/runtime/doc/if_perl.txt
@@ -19,7 +19,7 @@ See |provider-perl| for more information.
 			working: >
 				:perl print "Hello"
 
-:[range]perl << [endmarker]
+:[range]perl << [trim] [{endmarker}]
 {script}
 {endmarker}
 			Execute perl script {script}.
diff --git a/runtime/doc/if_pyth.txt b/runtime/doc/if_pyth.txt
index 45accc2e03..415a58ec71 100644
--- a/runtime/doc/if_pyth.txt
+++ b/runtime/doc/if_pyth.txt
@@ -19,17 +19,16 @@ Commands						*python-commands*
 			the `:python` command is working: >vim
 				:python print "Hello"
 
-:[range]py[thon] << [endmarker]
+:[range]py[thon] << [trim] [{endmarker}]
 {script}
 {endmarker}
 			Execute Python script {script}.  Useful for including
 			python code in Vim scripts.  Requires Python, see
 			|script-here|.
 
-The {endmarker} below the {script} must NOT be preceded by any white space.
-
 If [endmarker] is omitted from after the "<<", a dot '.' must be used after
-{script}, like for the |:append| and |:insert| commands.
+{script}, like for the |:append| and |:insert| commands.  Refer to
+|:let-heredoc| for more information.
 
 Example: >vim
 	function! IcecreamInitialize()
@@ -597,12 +596,12 @@ variants explicitly if Python 3 is required.
 
 							*:py3* *:python3*
 :[range]py3 {stmt}
-:[range]py3 << [endmarker]
+:[range]py3 << [trim] [{endmarker}]
 {script}
 {endmarker}
 
 :[range]python3 {stmt}
-:[range]python3 << [endmarker]
+:[range]python3 << [trim] [{endmarker}]
 {script}
 {endmarker}
 	The `:py3` and `:python3` commands work similar to `:python`.  A
diff --git a/runtime/doc/if_ruby.txt b/runtime/doc/if_ruby.txt
index d88f59eb73..a5aaac1a5f 100644
--- a/runtime/doc/if_ruby.txt
+++ b/runtime/doc/if_ruby.txt
@@ -19,15 +19,15 @@ downloading Ruby there.
 :rub[y] {cmd}		Execute Ruby command {cmd}.  A command to try it out: >
 				:ruby print "Hello"
 
-:rub[y] << [endmarker]
+:rub[y] << [trim] [{endmarker}]
 {script}
 {endmarker}
 			Execute Ruby script {script}.
-			The {endmarker} after {script} must NOT be preceded by
-			any white space.
 
 			If [endmarker] is omitted, it defaults to a dot '.'
-			like for the |:append| and |:insert| commands.
+			like for the |:append| and |:insert| commands.  Refer
+			to |:let-heredoc| for more information.
+
 
 			This form of the |:ruby| command is mainly useful for
 			including ruby code in vim scripts.
diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index b3be11efdb..465c83e6ab 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -247,12 +247,12 @@ arguments separated by " " (space) instead of "\t" (tab).
         :lua =jit.version
 <
                                                                 *:lua-heredoc*
-:lua << [endmarker]
+:lua << [trim] [{endmarker}]
 {script}
 {endmarker}
-    Executes Lua script {script} from within Vimscript. {endmarker} must NOT
-    be preceded by whitespace. You can omit [endmarker] after the "<<" and use
-    a dot "." after {script} (similar to |:append|, |:insert|).
+    Executes Lua script {script} from within Vimscript. You can omit
+    [endmarker] after the "<<" and use a dot "." after {script} (similar to
+    |:append|, |:insert|). Refer to |let-heredoc| for more information.
 
     Example: >vim
         function! CurrentLineInfo()