Helps to reveal more struction in the dominator tree that is normally lost from cross links added by call sites, allocation sites, inlining, etc.
Change-Id: Ib59350f9926324e6c53333388709ce4964c3f88b
Reviewed-on: https://dart-review.googlesource.com/c/94300
Reviewed-by: Aart Bik <ajcbik@google.com>