* 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/branches/ruby_2_0_0@47339 b2dd03c8-39d4-4d8f-98ff-823fe69b080e