Implement debugging of WOW64 processes in gdbserver

Implement debugging of WOW64 processes in gdbserver

gdbserver/ChangeLog:

2020-04-30  Hannes Domani  <ssbssa@yahoo.de>

	* configure.srv <x86_64-*-mingw*, x86_64-*-cygwin*> (srv_tgtobj):
	Add arch/i386.o.
	* win32-arm-low.cc (arm_num_regs): New function.
	(struct win32_target_ops): Use arm_num_regs.
	* win32-i386-low.cc (win32_get_current_dr): Adapt for WOW64
	processes.
	(i386_get_thread_context): Likewise.
	(i386_prepare_to_resume): Likewise.
	(i386_thread_added): Likewise.
	(i386_single_step): Likewise.
	(i386_fetch_inferior_register): Likewise.
	(i386_store_inferior_register): Likewise.
	(i386_arch_setup): Likewise.
	(i386_win32_num_regs): New function.
	(struct win32_target_ops): Use i386_win32_num_regs.
	* win32-low.cc (win32_get_thread_context): Adapt for WOW64
	processes.
	(win32_require_context): Likewise.
	(child_add_thread): Likewise.
	(do_initial_child_stuff): Likewise.
	(continue_one_thread): Likewise.
	(win32_process_target::resume): Likewise.
	(load_psapi): Likewise.
	(win32_add_all_dlls): Likewise.
	(maybe_adjust_pc): Likewise.
	(win32_process_target::qxfer_siginfo): Likewise.
	(initialize_low): Likewise.
	* win32-low.h (struct win32_target_ops): Change num_regs to
	callback function.