Correctly handle the Proxy IsCallable and IsConstructor information (#4264)

The `IsCallable(target)` and `IsConstructor(target)` info
can't be stored in the target/handler values.
If the input for the ProxyCreate was a revocable Proxy the original target's
callable/constructor information must be retained even after the
Proxy was revoked.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.usz@partner.samsung.com

jerry-core/ecma/base/ecma-gc.c

@@ -786,7 +786,11 @@ ecma_gc_mark (ecma_object_t *object_p) /**< object to mark from */
       case ECMA_OBJECT_TYPE_PROXY:
       {
         ecma_gc_mark_proxy_object (object_p);
-        break;
+        /* No need to free the properties of a proxy (there should be none).
+         * Aside from the tag bits every other bit should be zero,
+         */
+        JERRY_ASSERT ((object_p->u1.property_list_cp & ~JMEM_TAG_MASK) == 0);
+        return;
       }
 #endif /* ENABLED (JERRY_BUILTIN_PROXY) */
       case ECMA_OBJECT_TYPE_BOUND_FUNCTION:
@@ -1499,8 +1503,12 @@ ecma_gc_free_object (ecma_object_t *object_p) /**< object to free */
 #if ENABLED (JERRY_BUILTIN_PROXY)
     case ECMA_OBJECT_TYPE_PROXY:
     {
-      ext_object_size = sizeof (ecma_proxy_object_t);
-      break;
+      /* No need to free the properties of a proxy (there should be none).
+       * Aside from the tag bits every other bit should be zero,
+       */
+      JERRY_ASSERT ((object_p->u1.property_list_cp & ~JMEM_TAG_MASK) == 0);
+      ecma_dealloc_extended_object (object_p, sizeof (ecma_proxy_object_t));
+      return;
     }
 #endif /* ENABLED (JERRY_BUILTIN_PROXY) */
     case ECMA_OBJECT_TYPE_FUNCTION:

jerry-core/ecma/base/ecma-globals.h

@@ -2128,6 +2128,10 @@ do \
 #if ENABLED (JERRY_BUILTIN_PROXY)
 /**
  * Description of Proxy objects.
+ *
+ * A Proxy object's property list is used to store extra information:
+ *  * The "header.u1.property_list_cp" 1st tag bit stores the IsCallable information.
+ *  * The "header.u1.property_list_cp" 2nd tag bit stores the IsConstructor information.
  */
 typedef struct
 {