Fix a few issues breaking cctest/test-lockers/Regress1433:

Fix a few issues breaking cctest/test-lockers/Regress1433:

o The thread local state in an isolate has to be initialized before
  it's used.
o v8::Locker was incorrectly tracking whether it's the topmost one.
o Waking the profiler thread on shutdown should not leave the
  semaphore counter in an inconsitent state.

R=fschneider@chromium.org
BUG=v8:1522
TEST=cctest/test-lockers/Regress1433

Committed: http://code.google.com/p/v8/source/detail?r=8537

[fschneider, 2011-07-05 15:11:42]

LGTM. 

Thanks for fixing this! Maybe mention the issue (1522 I believe) in the BUG=
line.