Start to migrate pathops to builder

Change-Id: Ie95aeaa9154ba924db0fa400d50c9b80f5ac30c2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1056517
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Mike Reed <mike@reedtribe.org>
Reviewed-by: Florin Malita <fmalita@google.com>
7 files changed