Fix unreachable code in LocalGraph by making it imprecise there (#6048)

Followup to #6046 - the fuzzer found we missed handling the case of the entry itself
being unreachable, or of an unreachable loop later. Properly identifying unreachable
code requires a flow analysis, unfortunately, so this PR gives up on that and instead
allows LocalGraph to be imprecise in unreachable code. That avoids adding any
overhead, but does mean the IR may be slightly confusing when debugging. It does
not have any optimization downsides, however, as it only affects unreachable code.

Also add a dump() impl in that file which helps debugging.

0 files changed, 0 insertions, 0 deletions