In the process:
- Add a command-line flag --opt-code-positions to track source position information throughout optimized code.
- Add a subclass of the hydrogen graph builder to ensure that the source position is properly set on the graph builder for all generated hydrogen code.
- Overhaul handling of source positions in hydrogen to ensure they are passed through to generated code consistently and in most cases transparently.
Originally reviewed in this CL: https://codereview.chromium.org/24957003/
Review URL: https://codereview.chromium.org/29123008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17295 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
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
