* pinfo.cc (EnumProcessesNT): Avoid 0 pids.

(EnumProcesses9x): Ditto.
* sigproc.cc (remove_childe): Eliminate.
(proc_subproc): Move remove_child stuff here.
(wait_subproc): Synchronize with proc_subproc when error occurs.  Add more
debugging info.
* sigproc.h (procstuff): Add an entry.
* spawn.cc (spawn_guts): Add sigframe here.

winsup/cygwin/spawn.cc

@@ -289,6 +289,7 @@ spawn_guts (HANDLE hToken, const char * prog_arg, const char *const *argv,
 {
   BOOL rc;
   pid_t cygpid;
+  sigframe thisframe (mainthread);
 
   MALLOC_CHECK;