guest_avplayer_tests imports __cxa_throw from libc.prx, which is loaded
before libstdc++, but -static-libgcc gave it a private copy of
_Unwind_Resume. A failed Check threw through libc.prx's unwinder and the
landing pad of the test function resumed with the private one, so on
Linux every failure aborted in _Unwind_RaiseException_Phase2 instead of
printing its message from main. This is the unexplained Linux abort in
the intermittent guest_avplayer failures.
The test is now linked without the static runtime flags, as the AgcDriver,
Agc and VideoOut tests already are, so the unwinder comes from the same
library as __cxa_throw. A forced Check failure in TestPlayback aborted
before and now prints its message and exits with 1.
(cherry picked from commit fa5199cd8fef7f9c7ab9e83a441e15d16364a81d)