fix pathops unsortable angles

Pathops determines which edges are kept and discarded
by sorting intersections counterclockwise. An edge
may be unsortable if it is too close to a neighbor to
clearly be on its left or right.

If a pair of lines is unsortable, they are probably
nearly coincident, but just far enough apart to escape
the coincident test.

The current code correctly marks the lines as unsortable,
but returned a guess at the sorting order anyway. Instead,
preserve the unsorted-ness (unsorted mess?) and let
the decision of what to keep defer til later.

This triggered a couple of asserts that needed rewriting
or disabling, but fixes the bug in question and does not
regress the extended tests in debug or release.

Also, fix a debugging routine that bit-rotted.

TBR=reed@google.com

Bug: skia:8228
Change-Id: Ifab90c65837ed9656bb572c385fcc5c916348778
Reviewed-on: https://skia-review.googlesource.com/149620
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
Reviewed-by: Cary Clark <caryclark@skia.org>
5 files changed