1. Re-enable `HAVE_GETADDRINFO` detection on Windows
Commit d08ee3c83d (in 2013) added logic
that automatically assumed `getaddrinfo()` to be present for builds
with IPv6 enabled. As it turns out, certain toolchains (e.g. original
MinGW) by default target older Windows versions, and thus do not
support `getaddrinfo()` out of the box. The issue was masked for
a while by CMake builds forcing a newer Windows version, but that
logic got deleted in commit 8ba22ffb20.
Since then, some CI builds started failing due to IPv6 enabled,
`HAVE_GETADDRINFO` set, but `getaddrinfo()` in fact missing.
It also turns out that IPv6 works without `getaddrinfo()` since commit
67a08dca27 (from 2019, via #4662). So,
to resolve all this, we can now revert the initial commit, thus
restoring `getaddrinfo()` detection and support IPv6 regardless of its
outcome.
Reported-by: Daniel Stenberg
2. Omit `bcrypt` with original MinGW
Original (aka legacy/old) MinGW versions do not support `bcrypt`
(introduced with Vista). We already have logic to handle that in
`lib/rand.c` and autotools builds, where we do not call the
unsupported API and do not link `bcrypt`, respectively, when using
original MinGW.
This patch ports that logic to CMake, fixing the link error:
`c:/mingw/bin/../lib/gcc/mingw32/9.2.0/../../../../mingw32/bin/ld.exe: cannot find -lbcrypt`
Ref: https://ci.appveyor.com/project/curlorg/curl/builds/44624888/job/40vle84cn4vle7s0#L508
Regression since 76172511e7Fixes#9214Fixes#9393Fixes#9395Closes#9396
7cd400a4d2