Keep track of the number of unsupported steps

Dependencies

• [2] NJXD2ABJ Abort unsupported build steps
• [*] MHVIT4JY Split hydra-queue-runner.cc more
• [*] IK2UBDAU Revive jobset scheduling
• [*] 24BMQDZA Start of single-process hydra-queue-runner
• [*] DWFTK56E Keep track of how many threads are waiting
• [*] SOB276BA Keep some statistics for the binary cache stores
• [*] HJOEIMLR Refactor
• [*] DODOGD7M Send queue runner stats to statsd

Change contents

• edit in src/hydra-queue-runner/dispatcher.cc at line 330
  [2.4762]

  [5.1305]
  +

  + size_t count = 0;
• edit in src/hydra-queue-runner/dispatcher.cc at line 346
  [2.5131]

  [2.5131]
  + if (!supported)

  + count++;

  +
• edit in src/hydra-queue-runner/dispatcher.cc at line 404
  [2.6901]

  [2.6901]
  +

  + nrUnsupportedSteps = count;
• edit in src/hydra-queue-runner/hydra-queue-runner.cc at line 526
  [7.305]

  [8.1258]
  + root.attr("nrUnsupportedSteps", nrUnsupportedSteps);
• edit in src/hydra-queue-runner/state.hh at line 358
  [7.337]

  [9.5760]
  + counter nrUnsupportedSteps{0};
• edit in src/script/hydra-send-stats at line 37
  [10.1320]

  [10.1320]
  + gauge("hydra.queue.steps.unsupported", $json->{nrUnsupportedSteps});