mac: dyld fatal errors appear as abort() on 10.12
mac: dyld fatal errors appear as abort() on 10.12

In 10.12, dyld calls abort_with_payload() on fatal error from
dyld::halt(). In previous 10.12 betas, abort_with_payload() caused the
process to appear to terminate as exit(1). This was weird, so I filed
https://openradar.appspot.com/26894758. In 10.12db4 16A270f, Apple seems
to have fixed this bug. abort_with_payload() as used by dyld now causes
the process to appear to terminate as abort() as I had requested.

A Crashpad test that assures Crashpad’s ability to catch dyld crashes
needs its expectations updated with each change to a process’ apparent
termination code. It’s updated to expect SIGABRT on 10.12 or later. No
concessions are made for previous 10.12 betas or their buggy exit(1)
behavior. Nobody should be running any 10.12 beta prior to 10.12db4
16A270f now or at any point in the future.

This undoes (redoes) 335ef494677f.

BUG=crashpad:120
TEST=crashpad_snapshot_test MachOImageAnnotationsReader.CrashDyld

Change-Id: I13b330ac83fc9b33907ac172d35983974b8910f0
Reviewed-on: https://chromium-review.googlesource.com/365920
Reviewed-by: Robert Sesek <f55ad94e336f3a28322d0a25d280221ea9daf7a3@chromium.org>

atom/crashpad,chromium/crashpad,atom/crashpad,chromium/crashpad,chromium/crashpad,atom/crashpad