Make target_wait options use enum flags

Make target_wait options use enum flags

This changes TARGET_WNOHANG to be a member of an enum, rather than a
define, and also adds a DEF_ENUM_FLAGS_TYPE for this type.  Then, it
changes target_wait and the various target wait methods to use this
type rather than "int".

This didn't catch any bugs, but it seems like a decent cleanup
nevertheless.

I did not change deprecated_target_wait_hook, since that's only used
out-of-tree (by Insight), and there didn't seem to be a need.

I can't build some of these targets, so I modified them on a
best-effort basis.  I don't think this patch should go in before the
release branch is made.

gdb/ChangeLog
2020-09-18  Tom Tromey  <tromey@adacore.com>

	* windows-nat.c (struct windows_nat_target) <wait>: Update.
	(windows_nat_target::wait): Update.
	* target/wait.h (enum target_wait_flag): New.  Use
	DEF_ENUM_FLAGS_TYPE.
	* target/target.h (target_wait): Change type of options.
	* target.h (target_options_to_string, default_target_wait):
	Update.
	(struct target_ops) <wait>: Change type of options.
	* target.c (target_wait, default_target_wait, do_option): Change
	type of "options".
	(target_options_to_string): Likewise.
	* target-delegates.c: Rebuild.
	* target-debug.h (target_debug_print_target_wait_flags): Rename
	from target_debug_print_options.
	* sol-thread.c (class sol_thread_target) <wait>: Update.
	(sol_thread_target::wait): Update.
	* rs6000-nat.c (class rs6000_nat_target) <wait>: Update.
	(rs6000_nat_target::wait): Update.
	* remote.c (class remote_target) <wait, wait_ns, wait_as>:
	Update.
	(remote_target::wait_ns, remote_target::wait_as): Change type of
	"options".
	(remote_target::wait): Update.
	* remote-sim.c (struct gdbsim_target) <wait>: Update.
	(gdbsim_target::wait): Update.
	* record-full.c (class record_full_base_target) <wait>: Update.
	(record_full_wait_1): Change type of "options".
	(record_full_base_target::wait): Update.
	* record-btrace.c (class record_btrace_target) <wait>: Update.
	(record_btrace_target::wait): Update.
	* ravenscar-thread.c (struct ravenscar_thread_target) <wait>:
	Update.
	(ravenscar_thread_target::wait): Update.
	* procfs.c (class procfs_target) <wait>: Update.
	(procfs_target::wait): Update.
	* obsd-nat.h (class obsd_nat_target) <wait>: Update.
	* obsd-nat.c (obsd_nat_target::wait): Update.
	* nto-procfs.c (struct nto_procfs_target) <wait>: Update.
	(nto_procfs_target::wait): Update.
	* nbsd-nat.h (struct nbsd_nat_target) <wait>: Update.
	* nbsd-nat.c (nbsd_wait): Change type of "options".
	(nbsd_nat_target::wait): Update.
	* linux-thread-db.c (class thread_db_target) <wait>: Update.
	(thread_db_target::wait): Update.
	* linux-nat.h (class linux_nat_target) <wait>: Update.
	* linux-nat.c (linux_nat_target::wait): Update.
	(linux_nat_wait_1): Update.
	* infrun.c (do_target_wait_1, do_target_wait): Change type of
	"options".
	* inf-ptrace.h (struct inf_ptrace_target) <wait>: Update.
	* inf-ptrace.c (inf_ptrace_target::wait): Update.
	* go32-nat.c (struct go32_nat_target) <wait>: Update.
	(go32_nat_target::wait): Update.
	* gnu-nat.h (struct gnu_nat_target) <wait>: Update.
	* gnu-nat.c (gnu_nat_target::wait): Update.
	* fbsd-nat.h (class fbsd_nat_target) <wait>: Update.
	* fbsd-nat.c (fbsd_nat_target::wait): Update.
	* darwin-nat.h (class darwin_nat_target) <wait>: Update.
	* darwin-nat.c (darwin_nat_target::wait): Update.
	* bsd-uthread.c (struct bsd_uthread_target) <wait>: Update.
	(bsd_uthread_target::wait): Update.
	* aix-thread.c (class aix_thread_target) <wait>: Update.
	(aix_thread_target::wait): Update.

gdbserver/ChangeLog
2020-09-18  Tom Tromey  <tromey@adacore.com>

	* netbsd-low.h (class netbsd_process_target) <wait>: Update.
	* netbsd-low.cc (netbsd_waitpid, netbsd_wait)
	(netbsd_process_target::wait): Change type of target_options.
	* win32-low.h (class win32_process_target) <wait>: Update.
	* win32-low.cc (win32_process_target::wait): Update.
	* target.h (class process_stratum_target) <wait>: Update.
	(mywait): Update.
	* target.cc (mywait, target_wait): Change type of "options".
	* linux-low.h (class linux_process_target) <wait, wait_1>:
	Update.
	* linux-low.cc (linux_process_target::wait)
	(linux_process_target::wait_1): Update.