* debug.cc (threadname_init): Pass name of lock as arg 2 of new_muto.
* malloc.cc (malloc_init): Ditto.
* sigproc.cc (sigproc_init): Ditto.
* exceptions.cc (events_init): Ditto.
(call_handler): Eliminate special case for hExeced. Report locked thread in
debugging output.
* fhandler.cc (fhandker_pipe::fhandler_pipe): Propagate device type to base
class.
* fhandler.h (fhandler_pipe): Ditto.
* hinfo.cc (hinfo::build_fhandler): Pass specific type of pipe to constructor.
* spawn.cc (spawn_guts): Eliminate dependency on signal when waiting for
subprocess.
* strace.cc: Remove obsolete #ifdef.
* sync.cc (muto::muto): Save the name of the muto.
(muto:~muto): Also release the muto.
* sync.h: Add a muto name field.
* select.cc (peek_pipe): Avoid doing a PeekNamedPipe on the write end of a
pipe.
(call_handler): Allow signals to be sent even if signalled thread is stopped.
Change order of signal_arrived arming/waiting threads clearing to eliminate a
race.
(reset_signal_arrived): New helper function.
* malloc.cc (malloc_init): Use mutos so that signal handler can keep track of
who owns the lock.
(__malloc_lock): Ditto.
(__malloc_unlock): Ditto.
* sync.h (new_muto): Actually use a muto for the "buffer".
* Makefile.in: Fix a dependency.
* debug.cc (iscygthread): New function.
* debug.h: Declare it.
* exceptions.cc (set_process_mask): Flush pending signals.
(handle_sigsuspend): No need to flush pending signals.
(call_handler): Refine previous tests of muto ownership. Only clear wait()'s
when we have definitely responded to a signal.
* fhandler_console.cc (fhandler_console::read): Don't set EINTR if executing in
a "cygwin" thread.
* sigproc.cc (proc_subproc): Use second argument to control whether CLEARWAIT
actually sets "signalled" flag.
* sync.h (muto): Add 'unstable' method.
