1Regression test for b/140507091: Check that an explicit null check is
2emitted for a volatile field load on ARM64 at the beginning of the
3Baker read barrier thunk, so that a null holder object is properly
4caught (and throws a NullPointerException as expected), instead of
5trigerring a SIGSEGV, when the Concurrent Copying GC is in the marking
6phase.
7