Reporduces with the latest OI.
I made a typo while refactoring for 7020521, in stubGenerator_x86_64.cpp:
address generate_generic_copy(const char *name,
address byte_copy_entry, address short_copy_entry,
address int_copy_entry, address long_copy_entry,
address oop_copy_entry, address checkcast_copy_entry)
The order of arguments is wrong, entry_oop_arraycopy and entry_jlong_arraycopy should be swapped. With compressed oops this would cause stomping, among other things.