patch 9.1.1232: Vim script is missing the tuple data type

Problem:  Vim script is missing the tuple data type
Solution: Add support for the tuple data type
          (Yegappan Lakshmanan)

closes: #16776

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index bda20f5..f341fd4 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3799,8 +3799,12 @@
 		if (eq != NULL)
 		{
 		    eq = skipwhite(eq);
-		    if (vim_strchr((char_u *)"+-*/%", *eq) != NULL)
+		    if (vim_strchr((char_u *)"+-*/%.", *eq) != NULL)
+		    {
+			if (eq[0] == '.' && eq[1] == '.')
+			    ++eq;
 			++eq;
+		    }
 		}
 		if (p == NULL || p == eap->cmd || *eq != '=')
 		{