* child_info.h: Reset magic number.

(child_info_spawn::wait_for_myself): Move function to sigproc.cc.
* pinfo.cc (is_toplevel_proc): Delete unneeded variable.
* sigproc.cc (child_info_spawn::wait_for_myself): Move function from header to
here.  Do all setup required to properly wait for top-level execed process to
exit.
* spawn.cc (child_info_spawn::worker): Attempt to properly handle _P_DETACH.
Set wr_proc_pipe if top-level process even when execing.  Just call
wait_for_myself() to...  wait for myself.  Don't call cleanup twice.

winsup/cygwin/sigproc.cc

@@ -911,6 +911,16 @@ cygheap_exec_info::alloc ()
 					     + (nprocs * sizeof (children[0])));
 }
 
+void
+child_info_spawn::wait_for_myself ()
+{
+  myself.set_rd_proc_pipe (rd_proc_pipe);
+  ForceCloseHandle (wr_proc_pipe);
+  wr_proc_pipe = NULL;
+  myself.remember (false);
+  WaitForSingleObject (ev, INFINITE);
+}
+
 void
 child_info::cleanup ()
 {