patch 9.0.1152: class "implements" argument not implemented

Problem:    Class "implements" argument not implemented.
Solution:   Implement "implements" argument.  Add basic checks for when a
            class implements an interface.

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1152,
 /**/
     1151,
 /**/