Do not leak message object beyond try-catch.

src/compiler/ast-graph-builder.cc

Index: src/compiler/ast-graph-builder.cc
diff --git a/src/compiler/ast-graph-builder.cc b/src/compiler/ast-graph-builder.cc
index 0d01a5a08b9b37fa495684003baec4d061e96bfc..829e29befa2bcc20ec88e0827be0cc627c17091d 100644
--- a/src/compiler/ast-graph-builder.cc
+++ b/src/compiler/ast-graph-builder.cc
@@ -1474,6 +1474,12 @@ void AstGraphBuilder::VisitTryCatchStatement(TryCatchStatement* stmt) {
   }
   try_control.EndTry();
 
+  // Clear message object as we enter the catch block.
+  ExternalReference message_object =
+      ExternalReference::address_of_pending_message_obj(isolate());
+  Node* the_hole = jsgraph()->TheHoleConstant();
+  BuildStoreExternal(message_object, kMachAnyTagged, the_hole);
+
   // Create a catch scope that binds the exception.
   Node* exception = try_control.GetExceptionNode();
   Unique<String> name = MakeUnique(stmt->variable()->name());