Fix reintroduction of global variables that have been deleted.

Fix reintroduction of global variables that have been deleted.

Deletion of global properties puts 'the hole' in the global property
cell and updates the property details in the property dictionary with
the information that the property has been deleted. When setting
global properties that have been deleted in generated code we just
store the new value in the global property cell. This does not update
the property details in the property dictionary. Therefore, it looks
like the property is not there eventhough it was just reintroduced.

Perform 'the hole' checks in generated code for global property stores
and bail out of ICs and optimized code if storing to a property cell
that contains 'the hole'.

Review URL: http://codereview.chromium.org/6306014

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6508 ce2b1a6d-e550-0410-aec6-3dcde31c8c00