All our cached_dep magic was totally useless since we ended up using
the same identifier for native and cross deps. Just nuke all this
cached_dep code since it is very error-prone and improve the
identifier generation instead.
For instance, this is broken *right now* with the `type_name` kwarg.
Add a bunch of tests to ensure that all this actually works...
Closes https://github.com/mesonbuild/meson/issues/1736
Just checking that the version retrieved from the pkg-config file
matches is not enough. It's nearly tautological since it just checks
that we aren't returning garbage in dep.version(). Instead, check in the
test executable that the pkg-config version retrieved matches the
ZLIB_VERSION exported by zlib.
Also don't require zlib 1.2.8 since RHEL (EPEL) 7 still has 1.2.7 and we
don't really need 1.2.8 anyway.
Nirbheek Chauhan
Jussi Pakkanen