[vm] Remove no-longer-used definitions.
[vm] Remove no-longer-used definitions.

TEST=SDK builds.

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-release-x64-try

Change-Id: Ibf157c08090d6e150532003806e522a15c3526d2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/195064
Reviewed-by: Martin Kustermann <a35dd5b79fac84b2bb3b026a16b8becc55af5961@google.com>
Reviewed-by: Daco Harkes <930cbae0ca77f1954c53e32620d89cfcca318f00@google.com>
Commit-Queue: Tess Strickland <cce218d042444252b7ac446d60910fca7732559c@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