* pinfo.h (pinfo::init): Make third parameter non-optional and propagate change

throughout.
* pinfo.cc (set_myself): Pass INVALID_HANDLE_POINTER if h is NULL.
(pinfo::init): Make third parameter non-optional.  Eliminate use of PID_EXECED
as an argument.  Put setting of handle back inside loop but reorganize to try
to open it only when necessary.

winsup/cygwin/shared.cc

@@ -73,7 +73,7 @@ static char *offsets[] =
 };
 
 void * __stdcall
-open_shared (const char *name, int n, HANDLE &shared_h, DWORD size,
+open_shared (const char *name, int n, HANDLE& shared_h, DWORD size,
 	     shared_locations m, PSECURITY_ATTRIBUTES psa)
 {
   void *shared;