This makes sure that boilerplate objects for array literals with
non-constant elements (which will contain the hole at non-constant
positions) will not cause prototype chain lookups when generating
optimized code.

R=erik.corry@gmail.com
BUG=chromium:123512
TEST=mjsunit/regress/regress-123512

Review URL: https://chromiumcodereview.appspot.com/10105025

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@11350 ce2b1a6d-e550-0410-aec6-3dcde31c8c00