Preserve error message during finally block in try..finally.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index 7871f4e1cb467b3ca853d0a17e4bc35072b07deb..8c7ee8834c8a4cc8c9005617c97614134e27c419 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -955,6 +955,12 @@ ExternalReference ExternalReference::scheduled_exception_address(
 }
 
 
+ExternalReference ExternalReference::address_of_pending_message_obj(
+    Isolate* isolate) {
+  return ExternalReference(isolate->pending_message_obj_address());
+}
+
+
 ExternalReference ExternalReference::address_of_min_int() {
   return ExternalReference(reinterpret_cast<void*>(&double_constants.min_int));
 }