patch 9.0.1390: FOR_ALL_ macros are defined in an unexpected file

Problem:    FOR_ALL_ macros are defined in an unexpected file.
Solution:   Move FOR_ALL_ macros to macros.h.  Add FOR_ALL_HASHTAB_ITEMS.
            (Yegappan Lakshmanan, closes #12109)
diff --git a/src/if_ruby.c b/src/if_ruby.c
index 8f9b356..dd0f5db 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -1147,7 +1147,7 @@
 	    hashitem_T  *hi;
 	    dictitem_T  *di;
 
-	    for (hi = ht->ht_array; todo > 0; ++hi)
+	    FOR_ALL_HASHTAB_ITEMS(ht, hi, todo)
 	    {
 		if (!HASHITEM_EMPTY(hi))
 		{