m68k.c (m68k_frame): Move before protos referencing it.

m68k.c (m68k_frame): Move before protos referencing it.

	* config/m68k/m68k.c (m68k_frame): Move before protos referencing it.
	(m68k_save_reg): Add boolean parameter `interrupt_handler'.
	(m68k_interrupt_function_p): New function.
	(m68k_handle_fndecl_attribute): Ditto.
	(m68k_compute_frame_layout): Ditto.
	(m68k_attribute_table): Define back-end specific attributes.
	(m68k_output_function_epilogue): Emit RTE instruction for interrupt
	functions.

Co-Authored-By: Bernardo Innocenti <bernie@develer.com>
From-SVN: r72329