* tool/instruction.rb: create `trace_` prefix instructions.

* compile.c (ADD_TRACE): do not add `trace` instructions but add
  TRACE link elements. TRACE elements will be unified with a next
  instruction as instruction information.

* vm_trace.c (update_global_event_hook): modify all ISeqs when
  hooks are enabled.

* iseq.c (rb_iseq_trace_set): added to toggle `trace_` instructions.

* vm_insnhelper.c (vm_trace): added.
  This function is a body of `trace_` prefix instructions.

* vm_insnhelper.h (JUMP): save PC to a control frame.

* insns.def (trace): removed.

* vm_exec.h (INSN_ENTRY_SIG): add debug output (disabled).


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60763 b2dd03c8-39d4-4d8f-98ff-823fe69b080e