infcall: stop_registers -> register_dummy_frame_dtor

infcall: stop_registers -> register_dummy_frame_dtor

With dummy_frame destructors GDB no longer has to use global stop_registers.
dummy_frame's registers can be now stored associated with their specific
dummy_frame.

gdb/ChangeLog
2015-05-13  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* infcall.c (struct dummy_frame_context_saver)
	(dummy_frame_context_saver_data_free, dummy_frame_context_saver_dtor)
	(dummy_frame_context_saver_drop, dummy_frame_context_saver_cleanup)
	(dummy_frame_context_saver_get_regs, dummy_frame_context_saver_setup):
	New.
	(call_function_by_hand_dummy): Move discard_cleanups of
	inf_status_cleanup before dummy_frame_push.  Call
	dummy_frame_context_saver_setup and prepare context_saver_cleanup.
	Use dummy_frame_context_saver_get_regs instead of stop_registers.
	* infcall.h (struct dummy_frame_context_saver)
	(dummy_frame_context_saver_drop, dummy_frame_context_saver_cleanup)
	(dummy_frame_context_saver_get_regs, dummy_frame_context_saver_setup):
	New declarations.
	* infcmd.c: Include infcall.h.
	(get_return_value): Add parameter ctx_saver, use it instead of
	stop_registers.
	(print_return_value): Add parameter ctx_saver, pass it.
	(struct finish_command_continuation_args): Add field ctx_saver.
	(finish_command_continuation): Update print_return_value caller.
	(finish_command_continuation_free_arg): Free also ctx_saver.
	(finish_forward): Call dummy_frame_context_saver_setup.
	* inferior.h (struct dummy_frame_context_saver): New declaration.
	(get_return_value): Add parameter ctx_saver.
	* python/py-finishbreakpoint.c (bpfinishpy_pre_stop_hook): Update
	get_return_value caller.