It's argued that /WX allows to keep better focus on new code, which
motivates its comeback...
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4718)
(Modified for 1.0.2 by adding selected PACKET_xx() functions and PRF, and
subsequent cleanup from commit eb633d03fe2db3666840dee8d0a2dbe491672dfc)
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 40425899200a3dea9ec3684d3eb80bcf50c99baf)