* dcrt0.cc (dll_crt0_1): Move exception list and constructor stuff earlier in

the process.  Use new second argument to set_myself.
(cygwin_dll_init): Initialize exception list and constructor stuff here.
(_dll_crt0): And here.  Also, deal with inherited pinfo shared memory region
from parent.
* pinfo.cc (set_myself): Accept a second argument signifying the a shared
memory region, passed from an execing parent.
(pinfo_init): Ditto.
* pinfo.h: Ditto.
* shared.h (child_info): Add a handle field to pass to child.
* spawn.cc (spawn_guts): Create a shared handle to pass to an execed child.
* winsup.h: Remove extraneous declaration.

winsup/cygwin/winsup.h

@@ -283,7 +283,6 @@ long __stdcall to_time_t (FILETIME * ptr);
 int __stdcall lock_pinfo_for_update (DWORD timeout);
 #endif
 void unlock_pinfo (void);
-void _stdcall set_myself (pid_t pid);
 
 /* Retrieve a security descriptor that allows all access */
 SECURITY_DESCRIPTOR *__stdcall get_null_sd (void);