Merge branch 'ps/platform-compat-fixes'

Various platform compatibility fixes split out of the larger effort to use Meson as the primary build tool. * ps/platform-compat-fixes: t6006: fix prereq handling with `test_format ()` http: fix build error on FreeBSD builtin/credential-cache: fix missing parameter for stub function t7300: work around platform-specific behaviour with long paths on MinGW t5500, t5601: skip tests which exercise paths with '[::1]' on Cygwin t3404: work around platform-specific behaviour on macOS 10.15 t1401: make invocation of tar(1) work with Win32-provided one t/lib-gpg: fix setup of GNUPGHOME in MinGW t/lib-gitweb: test against the build version of gitweb t/test-lib: wire up NO_ICONV prerequisite t/test-lib: fix quoting of TEST_RESULTS_SAN_FILE