Remove code related to extended-opcode.

- This support was removed one year ago.

(cherry-pick from commit 18b65cbb3ec6634618bd3240a692507432e634b5)

Change-Id: I1154e518dc8a15220f2fcb163056570030492bb0
Change exception message for ArrayStoreException.

The exception message is tested in SystemTest. I'm not sure
what's worse: Changing the dalvik message or changing the test
to be happy with both messages.

(I assume the art message is the one we chose because it's more
recent.)

Change-Id: Ia68641a05f992ab5a949add865fb3f7bb46e61be