Change the tests which looks at the number of scripts in the VM after startup to ignore native scripts without name.

Native scripts without name are currently only the script holding the empty script and the script holding the source for the empty function. These two unnamed scripts are created for each context. When running with snapshot an additional context is created during startup adding two more native scripts that in the non-snapshot case.
Review URL: http://codereview.chromium.org/39333

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1448 ce2b1a6d-e550-0410-aec6-3dcde31c8c00