[vm] Print out canonical clusters in --print-snapshot-sizes-verbose.
[vm] Print out canonical clusters in --print-snapshot-sizes-verbose.

TEST=Manual use of the flag.

Cq-Include-Trybots: luci.dart.try:vm-kernel-linux-debug-x64-try,vm-kernel-nnbd-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-kernel-precomp-nnbd-linux-debug-x64-try
Change-Id: I4c506848f97f6b9a3f1455f90872093497c853a8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/188287
Commit-Queue: Tess Strickland <cce218d042444252b7ac446d60910fca7732559c@google.com>
Reviewed-by: Ryan Macnak <d738b7f001baf9789095d7dc549cff6de60b011d@google.com>
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