Issue 1:
I'm submitting a ...

[] bug report
[ x ] feature request
[ ] support request

Current behavior

Querying ngContent with a superclass doesn't work.

Expected behavior

Querying ngContent with a superclass should work.

Minimal reproduction of the problem with instructions

Currently, if you have a component that uses ng-content inside of its template, it can render out whatever you pass to it. (ie. any other component or html). However referencing this component is only possible if you know exactly what component it will be.

@ContentChildren(Component1) myComponent;

In the case where you don't know, you can't select it. My request would be that you can select the components off a super class. Say, Component1 extends MySuperClass and Component2 extends MySuperClass you can select their instances like so:

@ContentChildren(MySuperClass) myComponents;

What is the motivation / use case for changing the behavior?

The motivation behind this is allowing dynamic components to be injected yet allow their instance to be referenced by their parent component. In my particular use-case I am allowing the developer to build pages of a wizard containing whatever component they need -- I then assume that they have a class or interface on them that they share so that I can call functions on them like, say, validate so I can move forward in the wizard.

<wizard>
<page>
<component1></component1>
</page>
<page>
<component2></component2>
</page>
</wizard>

Please tell us about your environment:

Windows 10, Angular 2.0.1, WebStorm, Webpack/Gulp

Additional Notes

A workaround currently is instead to pass the components in as a config (say an array of components) and then refer to them that way. However it would be nice to be able to reference the instances of the components injected dynamically via ng-content

I would also think that this may be related to #8580 in the sense that I would expect these two scenarios to work the same. The linked issues mentions that super class selectors should work (at least when the components aren't dynamically defined).

Issue 2:
I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/angular/angular/blob/master/CONTRIBUTING.md#question

Current behavior

If i have InjectionToken i cant assign it to ViewChildren or ContentChildren as mentioned in #12758 Maybe due to changes of Typescript.

Expected behavior

This code is working if you type it to <any> but without it cant be compiled using typescript.

Minimal reproduction of the problem with instructions

This will not compile :).

export const SomeClassToken = new InjectionToken<SomeClass>('SomeClassToken');

export class TestClass
{
@ViewChildren(SomeClassToken)
public children: QueryList<SomeClass>;
}

What is the motivation / use case for changing the behavior?

It should compile, because it works if typed to <any>.

Environment

Angular version: 5.1.2

Browser:
During compilation
- [ ] Chrome (desktop) version XX
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [ ] IE version XX
- [ ] Edge version XX

For Tooling issues:
- Typescript version: 2.5.3
- Node version: 8.1.2
- Platform: Windows

Others: