Only make function literals in top-level object literals pretenured and...

Only make function literals in top-level object literals pretenured and constant function properties.

This change is a refinement of http://code.google.com/p/v8/source/detail?r=7283. Making all
function literals inside object literals constant function properties causes us to lose map
sharing. This hurts code where many object literals are created.

The idea is that top-level code is mostly executed once and functions inside top-level
object literals remain fast with this change.

BUG=v8:1795
Review URL: http://codereview.chromium.org/8746018

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10096 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/parser.cc

@@ -3844,9 +3844,11 @@ Expression* Parser::ParseObjectLiteral(bool* ok) {
     ObjectLiteral::Property* property =
         new(zone()) ObjectLiteral::Property(key, value);
 
-    // Mark object literals that contain function literals and pretenure the
-    // literal so it can be added as a constant function property.
-    if (value->AsFunctionLiteral() != NULL) {
+    // Mark top-level object literals that contain function literals and
+    // pretenure the literal so it can be added as a constant function
+    // property.
+    if (top_scope_->DeclarationScope()->is_global_scope() &&
+        value->AsFunctionLiteral() != NULL) {
       has_function = true;
       value->AsFunctionLiteral()->set_pretenure();
     }