Fix refcounting bug in lookupCnsUHelper

Summary: Fixes #2544

Reviewed By: @ptarjan

Differential Revision: D1628194
Simplify File Outline Code

Summary: We don't need to do naming. Actually, the AST is closer to what we really want anyways.

Reviewed By: @jwatzman

Differential Revision: D1615948
backport PHP bugfix #55504

Summary: We didn't look for the end of the boundary correctly.

See:
- https://github.com/php/php-src/commit/994df9f1d1bfd5f6e6b81f32161acc2812d260a7#diff-eb2caada78cc7ed9dbeabe07d25eecf4
- https://bugs.php.net/bug.php?id=55504
Closes https://github.com/facebook/hhvm/pull/4013

Reviewed By: @fredemmott

Differential Revision: D1626104