Previously, the (currently disabled) undecorated parent migration in
ngcc would produce errors when a base class could not be determined
statically or when a class extends from a class in another package. This
is not ideal, as it would cause the library to fail compilation without
a workaround, whereas those problems are not guaranteed to cause issues.
Additionally, inheritance chains were not handled. This commit reworks
the migration to address these limitations.
PR Close#33362
2e5e1dd5f5