Skip copying from caller's frame when unparking virtual threads

It fixes a NullPointerException and segfault in
ThreadPerTaskExecutorTest.

It's likely because copying registers from caller frame shouldn't be
needed because it overrwrites the correct value at a particular dex
instruction that the virtual thread is executing.

Flag: com.android.art.flags.virtual_thread_impl_v1
Bug: 434619020
Test: ThreadPerTaskExecutorTest
Change-Id: Ic2c98f14dcbbfe416a725258bdce161cc3c5c628
4 files changed