Port r17073 (ba68149)
Original commit message:
- Detect unreachable basic blocks of code either following an unconditional deopt or after a provably untaken branch of HBranch or HCompareObjectEqAndBranch instructions.
- Emit dummy uses in unreachable blocks during Hydrogen -> Lithium translation.
BUG=chromium:258519
R=mstarzinger@chromium.org, plind44@gmail.com
Review URL: https://codereview.chromium.org/25708004
Patch from Balazs Kilvady <kilvadyb@homejinni.com>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17084 ce2b1a6d-e550-0410-aec6-3dcde31c8c00