There are different `DebugNode`/`DebugElement` implementations (and
associated helper functions) for ViewEngine and Ivy. Additionally, these
classes/functions, which are defined inside the `core` package, are
imported by the `platform-browser` package.
Previously, this code was not tree-shaken as expected in Ivy. #30130
partially addressed the issue, but only for the case where `core` and
`platform-browser` end up in the same closure after webpack's scope
hoisting. In cases where this is not the case, our webpack/terser based
tooling is not capable of tree-shaking it.
This commit fixes the problem, by ensuring that the code retained in Ivy
mode (due to the cross-package import) does not unnecessarily reference
`DebugNode`/`DebugElement`, allowing the code to be tree-shaken away.
This results in a 7.6KB reduction in the size of the main angular.io
bundle.
Jira issue: [FW-1802](https://angular-team.atlassian.net/browse/FW-1802)
PR Close#35003
669df70da5