The reachability of a bytecode is implied by a live environment reaching
the bytecode during the abstract control flow simulation of the bytecode
iteration perfromed by the graph builder. There is no need to compute it
upfront anymore.

Also, the upfront computation was only an approximation when it came to
the reachability of an exception handler. This is why several tests for
translation of exception handlers can now be enabled.

R=oth@chromium.org

Review URL: https://codereview.chromium.org/1645293003

Cr-Commit-Position: refs/heads/master@{#33634}