Enable settings used in TAP tests for MSVC builds
Certain settings from configuration or the Makefile infrastructure are
used by the TAP tests, but were not being set up by vcregress.pl. This
remedies those omissions. This should increase test coverage, especially
on the buildfarm.
Reviewed by Noah Misch
Discussion: https://postgr.es/m/
17093da5-e40d-8335-d53a-
2bd803fc38b0@dunslane.net
Backpatch to all live branches.