build: Include prefix in libdir & co.
Previously, when absolute `libdir` path was needed, it was joined with `prefix` on the spot. This meant the libraries used relative `install_dir` when `libdir` option was not passed. This in turn caused issues for NixOS’s patched Meson which needs absolute paths to be able to use them in generated GIR files. This commit initializes `bindir`, `libdir`, and `datadir` with `prefix` in the top-level meson.build.
prefix in 3 minutes and 21 seconds (queued for 1 second)1 job for