Remove some initialization checks based on source positions.

Remove some initialization checks based on source positions.

This depends on
http://codereview.chromium.org/8352039 and
http://codereview.chromium.org/8423005 .

Committed: http://code.google.com/p/v8/source/detail?r=9870

[Steven, 2011-10-31 14:29:02]

Some more init checks. PTAL.

[Jakob Kummerow, 2011-10-31 15:08:29]

LGTM.