Ivy definition looks something like this:
```
class MyService {
static ngInjectableDef = defineInjectable({
…
});
}
```
Here the argument to `defineInjectable` is well known public contract which needs
to be honored in backward compatible way between versions. The type of the
return value of `defineInjectable` on the other hand is private and can change
shape drastically between versions without effecting backwards compatibility of
libraries publish to NPM. To our users it is effectively an `OpaqueToken`.
By prefixing the type with `ɵ` we are communicating the the outside world that
the value is not public API and is subject to change without backward compatibility.
PR Close#23371
This adds compilation of @NgModule providers and imports into
ngInjectorDef statements in generated code. All @NgModule annotations
will be compiled and the @NgModule decorators removed from the
resultant js output.
All @Injectables will also be compiled in Ivy mode, and the decorator
removed.
PR Close#22458
`main()` function used to be needed to support dart, since dart
Does not allow top level statements. Since we no longer use dart
The need for `main()` has been removed.
In preparation for `Basel` and standardized way of running tests
we are removing `main()`
PR Close#21053
Victor Berchet
Jason Aden
Igor Minar
Miško Hevery
Alex Rickabaugh
Chuck Jazdzewski
Alex Eagle