meson: Add tests to suites

meson: Add tests to suites

Meson test has a concepts of suites, which allow tests to be grouped
together. This allows for a subtest of tests to be run only (say only
the tests for nir). A test can be added to more than one suite, but for
the most part I've only added a test to a single suite, though I've
added a compiler group that includes nir, glsl, and glcpp tests.

To use this you'll need to invoke meson test directly, instead of ninja
test (which always runs all targets). it can be invoked as:
`meson test -C builddir --suite $suitename` (meson test has addition
options that are pretty useful).

Tested-By: Gert Wollny <gert.wollny@collabora.com>
Acked-by: Eric Engestrom <eric.engestrom@intel.com>