patch 9.1.0394: Cannot get a list of positions describing a region

Problem:  Cannot get a list of positions describing a region
          (Justin M. Keyes, after v9.1.0120)
Solution: Add the getregionpos() function
          (Shougo Matsushita)

fixes: #14609
closes: #14617

Co-authored-by: Justin M. Keyes <justinkz@gmail.com>
Signed-off-by: Shougo Matsushita <Shougo.Matsu@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index 9259cde..192c3ee 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -41574,6 +41574,7 @@
 |matchbufline()|	all the matches of a pattern in a buffer
 |matchstrlist()|	all the matches of a pattern in a List of strings
 |getregion()|		get a region of text from a buffer
+|getregionpos()|	get a list of positions for a region
 
 
 Autocommands: ~