perl tap: Show die reason in TAP output

perl tap: Show die reason in TAP output

Install a $SIG{__DIE__} handler in the INIT block of Utils.pm that emits
the die message as a TAP diagnostic.  Previously, an unexpected die
(e.g. from safe_psql) produced only "no plan was declared" with no
indication of the actual error.  The handler also calls done_testing()
to suppress that confusing message.

Dies during compilation ($^S undefined) and inside eval ($^S == 1) are
left alone.

Author: Jelte Fennema-Nio <postgres@jeltef.nl>
Reviewed-by: Andrew Dunstan <andrew@dunslane.net>
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Zsolt Parragi <zsolt.parragi@percona.com>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/DFYFWM053WHS.10K8ZPJ605UFK@jeltef.nl
Discussion: https://postgr.es/m/20220222181924.eehi7o4pmneeb4hm%40alap3.anarazel.de