Add script to support per-line @suppress annotations in Phan

Add script to support per-line @suppress annotations in Phan

Adds the functionality of per-line @suppress annotations. Phan already
supports per-class or per-method annotations, but does not have any
per-line support due to the PHP AST only returning comments that are
class/property/method level docblocks.

This is a bit of a hack, but get's the job done. Removes the
PhanTypeInvalidLeftOperand issue from blacklist and suppresses it
to demonstrate the supression works as expected.

Change-Id: I5066b3b431fb69175a711ee366e95f31c7c47639