gdbserver/linux-low: turn some more static functions into private methods

gdbserver/linux-low: turn some more static functions into private methods

gdbserver/ChangeLog:
2020-04-02  Tankut Baris Aktemur  <tankut.baris.aktemur@intel.com>

	Turn some more static methods in linux-low into private methods
	of linux_process_target.

	* linux-low.cc (get_pc): Turn into...
	(linux_process_target::get_pc): ...this.
	(save_stop_reason): Turn into...
	(linux_process_target::save_stop_reason): ...this.
	(thread_still_has_status_pending_p): Turn into...
	(linux_process_target::thread_still_has_status_pending): ...this.
	(status_pending_p_callback): Turn into...
	(linux_process_target::status_pending_p_callback): ...this.
	(resume_stopped_resumed_lwps): Turn into...
	(linux_process_target::resume_stopped_resumed_lwps): ...this.
	(install_software_single_step_breakpoints): Turn into...
	(linux_process_target::install_software_single_step_breakpoints):
	...this.
	(single_step): Turn into...
	(linux_process_target::single_step): ...this.
	(linux_resume_one_lwp_throw): Turn into...
	(linux_process_target::resume_one_lwp_throw): ...this.
	(linux_resume_one_lwp): Turn into...
	(linux_process_target::resume_one_lwp): ...this.
	(resume_status_pending_p): Turn into...
	(linux_process_target::resume_status_pending): ...this.
	(need_step_over_p): Turn into...
	(linux_process_target::thread_needs_step_over): ...this.
	(linux_resume_one_thread): Turn into...
	(linux_process_target::resume_one_thread): ...this.
	(proceed_one_lwp): Turn into...
	(linux_process_target::proceed_one_lwp): ...this.
	(unsuspend_and_proceed_one_lwp): Turn into...
	(linux_process_target::unsuspend_and_proceed_one_lwp): ...this.

	Update the calls/references to the above functions below.

	(linux_process_target::handle_extended_wait)
	(linux_process_target::filter_event)
	(linux_process_target::wait_for_event_filtered)
	(linux_process_target::wait_1)
	(linux_process_target::move_out_of_jump_pad)
	(linux_process_target::start_step_over)
	(linux_process_target::resume)
	(linux_process_target::proceed_all_lwps)
	(regsets_store_inferior_registers)
	(linux_process_target::store_register)

	* linux-low.h (class linux_process_target)
	<get_pc>
	<save_stop_reason>
	<thread_still_has_status_pending>
	<status_pending_p_callback>
	<resume_stopped_resumed_lwps>
	<install_software_single_step_breakpoints>
	<single_step>
	<resume_one_lwp_throw>
	<resume_one_lwp>
	<resume_status_pending>
	<thread_needs_step_over>
	<resume_one_thread>
	<proceed_one_lwp>
	<unsuspend_and_proceed_one_lwp>: Declare.