Fix minor handle unsafety in exception throwing code.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 1482c4ca69ba5e9eead21010cd3506d55b588b1d..398213412cf36ce33be12fa4489d430660bb8696 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -2646,7 +2646,7 @@ MUST_USE_RESULT MaybeObject* JSProxy::DeletePropertyWithHandler(
     String* name_raw, DeleteMode mode) {
   Isolate* isolate = GetIsolate();
   HandleScope scope(isolate);
-  Handle<Object> receiver(this);
+  Handle<JSProxy> receiver(this);
   Handle<Object> name(name_raw);
 
   Handle<Object> args[] = { name };
@@ -2656,8 +2656,9 @@ MUST_USE_RESULT MaybeObject* JSProxy::DeletePropertyWithHandler(
 
   Object* bool_result = result->ToBoolean();
   if (mode == STRICT_DELETION && bool_result == GetHeap()->false_value()) {
+    Handle<Object> handler(receiver->handler());
     Handle<String> trap_name = isolate->factory()->LookupAsciiSymbol("delete");
-    Handle<Object> args[] = { Handle<Object>(handler()), trap_name };
+    Handle<Object> args[] = { handler, trap_name };
     Handle<Object> error = isolate->factory()->NewTypeError(
         "handler_failed", HandleVector(args, ARRAY_SIZE(args)));
     isolate->Throw(*error);
@@ -9672,8 +9673,9 @@ MaybeObject* JSObject::SetElement(uint32_t index,
   // Don't allow element properties to be redefined for external arrays.
   if (HasExternalArrayElements() && set_mode == DEFINE_PROPERTY) {
     Isolate* isolate = GetHeap()->isolate();
+    Handle<Object> receiver(this);
     Handle<Object> number = isolate->factory()->NewNumberFromUint(index);
-    Handle<Object> args[] = { Handle<Object>(this), number };
+    Handle<Object> args[] = { receiver, number };
     Handle<Object> error = isolate->factory()->NewTypeError(
         "redef_external_array_element", HandleVector(args, ARRAY_SIZE(args)));
     return isolate->Throw(*error);