* module/system/vm/traps.scm (frame-matcher): New helper.
(trap-at-procedure-call, trap-in-procedure, trap-in-dynamic-extent)
(trap-calls-in-dynamic-extent, trap-instructions-in-dynamic-extent)
(trap-instructions-in-procedure, trap-at-procedure-ip-in-range): Add
ability to trap on procedures that are closures.
(trap-at-source-location): Check source-closures first, to catch
source locations that are in nested procedures.
* module/system/vm/traps.scm (trap-frame-finish): Use frame-address
instead of frame-dynamic-link.
(trap-calls-to-procedure): New proc, traps on procedure calls and
their corresponding returns.
* module/system/vm/traps.scm (trap-frame-finish)
(trap-in-dynamic-extent, trap-calls-in-dynamic-extent)
(trap-instructions-in-dynamic-extent): New traps, for implementing
tracing, and the `finish' command.
* module/system/vm/trace.scm (trace-calls-in-procedure)
(trace-instructions-in-procedure): New tracing traps.
(vm-trace): Reimplement in terms of the new traps.
* module/system/vm/trap-state.scm (add-trap!): New helper; not used in
this commit, though.
* module/system/vm/traps.scm (new-disabled-trap): Don't manipulate the
VM trace level in the enable and disable handlers. Unfortunately, this
makes traps not work unless you enable hooks, but given that
vm_dispatch_hook has to set trace-level to 0, there needs to be an
object with a broader view of what traps are enabled. That object is
the hook state.
* module/system/vm/trap-state.scm (trap-state->trace-level): New
procedure.
(with-default-trap-handler): Add an optional trap-state argument. Now
makes sure that the vm-trace-level is set appropriately during the
execution of the thunk, allowing for breakpoints from recursive
prompts.
* module/system/vm/traps.scm: New module, implements higher-level traps
based on the VM hooks. Inspired by (ice-9 debugging traps). Instead of
the ice-9's variety, these traps have a procedural interface instead
of a GOOPS interface.
* module/Makefile.am: Add the new module.
