Add the GitHub Actions workflows for running RTLMeter.
Runs start daily, at 02:00 UTC, on ubuntu-24.04. There are 2 runs:
- Using GCC, with default verilator options
- Using Clang, with "--threads 4"
Each run uses a maximum of 2 runners in parallel (so max 4 in total),
and takes slightly over 2 hours to complete.
The jobs will fail if a benchmark is broken, so this already serves as a
regression test for the included designs.
For now, performance metrics are recorded as artefacts of the run but
not otherwise published.
Performance metrics are always recorded for all successful jobs, even if
some cases are failing.