Changeset 11062:fbce13fdad11

---------------------------

sim: don't ignore SIG_TRAP
By ignoring SIG_TRAP, using --debug-break <N> when not connected to

a debugger becomes a no-op.  Apparently this was intended to be a

feature, though the rationale is not clear.
If we don't ignore SIG_TRAP, then using --debug-break <N> when not

connected to a debugger causes the simulation process to terminate

at tick N.  This is occasionally useful, e.g., if you just want to

collect a trace for a specific window of execution then you can combine

this with --debug-start to do exactly that.
In addition to not ignoring the signal, this patch also updates

the --debug-break help message and deletes a handful of unprotected

calls to Debug::breakpoint() that relied on the prior behavior.