Win32 WEXITSTATUS too simplistic

win32.h says

/*
* Signal stuff
* WIN32 doesn't have wait(), so the return value for children
* is simply the return value specified by the child, without
* any additional information on whether the child terminated
* on its own or via a signal. These macros are also used
* to interpret the return value of system().
*/
#define WEXITSTATUS(w) (w)
#define WIFEXITED(w) (true)
#define WIFSIGNALED(w) (false)
#define WTERMSIG(w) (0)

I think this supposition has been pretty much proven false by recent
reports of silly "exit code" numbers from Win32 users, as for instance
here
http://archives.postgresql.org/pgsql-bugs/2006-12/msg00163.php
where the postmaster reports
server process exited with exit code -1073741819
from what I suspect is really the equivalent of a SIGSEGV trap,
ie, attempted access to already-deallocated memory. My calculator
says the above is equivalent to hex C0000005, and I say that this
makes it pretty clear that *some* parts of Windows put flag bits into
the process exit code. Anyone want to run down what we should really
be using instead of the above macros?

regards, tom lane