Move work to omit unnecessary ObjectLiteral stores to the numbering pass.

src/ast-numbering.cc

Index: src/ast-numbering.cc
diff --git a/src/ast-numbering.cc b/src/ast-numbering.cc
index 68dc65a79d35a4516796029d6293fc21d8f2fc87..4ec93eded0ee289fda1d2658ee82753637f5c48d 100644
--- a/src/ast-numbering.cc
+++ b/src/ast-numbering.cc
@@ -432,6 +432,10 @@ void AstNumberingVisitor::VisitObjectLiteral(ObjectLiteral* node) {
   for (int i = 0; i < node->properties()->length(); i++) {
     VisitObjectLiteralProperty(node->properties()->at(i));
   }
+  // Mark all computed expressions that are bound to a key that
+  // is shadowed by a later occurrence of the same key. For the
+  // marked expressions, no store code will be is emitted.
+  node->CalculateEmitStore(zone());
 }