[patch] recognise when an exec()d process terminates due to unhandled exception

[Brian Dessent]

Christopher Faylor wrote:

> That was going to be my first observation, actually.  I'm still trying
> to digest the patch but it seems like it wouldn't work well with the
> fork retry code.

The patch doesn't change any behavior though: in current Cygwin if the
thing we're exec()ing returns a Win32 exit code of C0000135 (or
whatever) then we retry creating it 5 times.  With the patch, we still
retry starting it 5 times but after the last one fails we recognise the
situation and print a message.

Brian