gdb: convert jit to new-style debug macros

gdb: convert jit to new-style debug macros

Here's a sample output, with infrun debug enabled as well to show
nesting:

    [infrun] fetch_inferior_event: enter
      [infrun] print_target_wait_results: target_wait (-1.0.0 [process -1], status) =
      [infrun] print_target_wait_results:   4116727.4116727.0 [process 4116727],
      [infrun] print_target_wait_results:   status->kind = stopped, signal = GDB_SIGNAL_TRAP
      [infrun] handle_inferior_event: status->kind = stopped, signal = GDB_SIGNAL_TRAP
      [infrun] start_step_over: enter
        [infrun] start_step_over: stealing global queue of threads to step, length = 0
        [infrun] operator(): step-over queue now empty
      [infrun] start_step_over: exit
      [infrun] handle_signal_stop: stop_pc=0x555555555229
      [infrun] handle_jit_event: handling bp_jit_event
      [jit] jit_read_descriptor: descriptor_addr = 0x5555555580b0
      [jit] jit_register_code: symfile_addr = 0x7000000, symfile_size = 15560
      [jit] jit_bfd_try_read_symtab: symfile_addr = 0x7000000, symfile_size = 15560
      [jit] jit_breakpoint_re_set_internal: breakpoint_addr = 0x555555555229
      [infrun] process_event_stop_test: BPSTAT_WHAT_SINGLE
      [infrun] process_event_stop_test: no stepping, continue
      [infrun] resume_1: step=1, signal=GDB_SIGNAL_0, trap_expected=1, current thread [process 4116727] at 0x555555555229
      [infrun] prepare_to_wait: prepare_to_wait
    [infrun] fetch_inferior_event: exit

gdb/ChangeLog:

	* jit.c (jit_debug_printf): New, use throughout file.

Change-Id: Ic0f5eb3ffc926fb555de4914e7dc1076ada63a97