Build-ids are required for doing certain kinds of performance tracing.
For example build-ids let Linux perf find the correct objects and
transfer them to other machines via "perf archive".
This adds an option to add -Wl,--build-id to the linker. It can be
enabled by passing -Dbuild_id=true to meson or --build-id to
package-release.sh.
Signed-off-by: Nicholas Fraser <nfraser@codeweavers.com>
* enable unity build for releases
* let the packaging script work wth relative paths
* add build option to enable building the test binaries; disabled by default
* disable unity build until it's been more tested
