* vm_core.h: add VM_FRAME_MAGIC_RESCUE to recognize normal block or
  rescue clause.
* vm.c (vm_exec): use VM_FRAME_MAGIC_RESCUE on at rescue/ensure.
* test/ruby/test_settracefunc.rb: should not invoke b_return at rescue
  clause.
  [Bug #9957]
* vm_dump.c (control_frame_dump): check VM_FRAME_MAGIC_RESCUE.
* vm_dump.c (vm_stack_dump_each): ditto.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46463 b2dd03c8-39d4-4d8f-98ff-823fe69b080e