gdb/

gdb/
	* jit.c: Include regcache.h.
	(jit_gdbarch_data, jit_frame_unwind): New static variables.
	(jit_unwind_reg_set_impl, free_reg_value_impl)
	(jit_unwind_reg_get_impl, jit_frame_sniffer)
	(jit_frame_unwind_stop_reason, jit_frame_this_id)
	(jit_frame_prev_register, jit_dealloc_cache)
	(jit_prepend_unwinder, jit_gdbarch_data_init): New functions.
	(jit_inferior_init): Prepend (new) pseudo unwinder by calling
	jit_prepend_unwinder.
	(_initialize_jit): Register new gdbarch data jit_gdbarch_data.