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.
diff --git a/src/alloc.c b/src/alloc.c
index 583ea87..e3e6d04 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -813,7 +813,7 @@
/*
* Add string "p" to "gap".
- * When out of memory "p" is freed and FAIL is returned.
+ * When out of memory FAIL is returned (caller may want to free "p").
*/
int
ga_add_string(garray_T *gap, char_u *p)