[vm] Add a glossary of terms used by the VM.
[vm] Add a glossary of terms used by the VM.

Change-Id: Iea8ab0a6d49a1bcfd0835761caf2446af3cb1228
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252280
Reviewed-by: Alexander Markov <239e774fd29abc1267878f57afe1a8a03e0ca887@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk