fix pathops fuzzers

Extreme values trigger asserts that in range
values allow.

Disable asserts and other tests to prevent
extreme values from crashing.

TBR=reed@google.com
BUG=644684. 644680, 644640
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2316173002

Review-Url: https://codereview.chromium.org/2316173002
3 files changed