Add ShortArrayCodeInput.

This is analogous to ByteArrayInputStream, and is hopefully useful
as-is to be the impedence matcher between CodeReader and InstructionCodec.

I also modified CodeInput's methods to throw EOFException, implementing
ShortArrayCodeInput to throw it in the expected cases.

Change-Id: Id46366590ed5a2607bc6672d040f9d11fa8a445d
Bonus: Fixed a comment in BytecodeArray that I happened to notice.
5 files changed