That better follows ECMA-262 (see 13.2 Creating Function Objects) and allows
to ignore nasty JS accessors for 'constructor' property.

BUG=v8:1172
TEST=test/mjsunit/regress/regress-1172.js

Review URL: http://codereview.chromium.org/6531037

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6849 ce2b1a6d-e550-0410-aec6-3dcde31c8c00