Fix DexInstructionIterator overrun bug

Handle cases where the dex instructions can go past the end of the
code item in dexlayout.

Since dexlayout runs before method verification, we need to be
careful to not go past the end of the code item.

Added test.

Bug: 67104794
Test: test-art-host

Change-Id: Idf7d51344659b2c75207bdf444e39f271feb8d3a
6 files changed