`NgModule` requires that `Component`s/`Directive`s/`Pipe`s are listed in
declarations, and that each `Component`s/`Directive`s/`Pipe` is declared
in exactly one `NgModule`. This change adds runtime checks to ensure
that these sementics are true at runtime.
There will need to be seperate set of checks for the AoT path of the
codebase to verify that same set of semantics hold. Due to current
design there does not seem to be an easy way to share the two checks
because JIT deal with references where as AoT deals with AST nodes.
PR Close#27604
e94975d109