Quick: Fix crash on fall-through out of method code.

Fix Quick crash when the last insn has a fall-through out of
the method's code. Allow creation of an out-of-method block
and at the end of MIRGraph::InlineMethod() check if that
block is reachable. If it is, punt to interpreter. Add tests
for unreachable if-lt and packed-switch as the last insn.

Also fix MIRGraph::ProcessCanSwitch() to treat the offset to
the data as signed. Jumping over the data with a goto and
using it from a switch further down is valid. This was also
crashing (presumably only on 64-bit dex2oat).

Thanks to Stephen Kyle (stephenckyle@googlemail.com) for the
bug report.

Bug: 19988134
Change-Id: I627f4137f61901897bfb9a5252741c6ded3a1adb