The `inject()` function was introduced with Ivy to support imperative
injection in factory/constructor contexts, such as directive or service
constructors as well as factory functions defined in `@Injectable` or
`InjectionToken`. However, `inject()` in a component/directive constructor
did not work due to a flaw in the logic for creating the internal factory
for components/directives.

The original intention of this logic was to keep `ɵɵdirectiveInject` tree-
shakable for applications which don't use any component-level DI. However,
this breaks the `inject()` functionality for component/directive
constructors.

This commit fixes that issue and adds tests for all the various cases in
which `inject()` should function. As a result `ɵɵdirectiveInject` is no
longer tree-shakable, but that's totally acceptable as any application that
uses `*ngIf` or `*ngFor` already contains this function. It's possible to
change how `inject()` works to restore this tree-shakability if needed.

PR Close #45991

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:
* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:
* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

… using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.

This change switches the cdk menu from using constructor injection to using the `inject` function. This was enabled by angular/angular#45991. This approach has a number of advantages:

* We can add and remove injectables without changing the public constructor signature
* It reduces the boilerplate of passing arguments through `super`
* It avoids long/messy constructor blocks in favor of simpler member definitions.
* This sidesteps a common pitfall of making `@Optional` injection (`null` if not provided) as an optional parameter (`undefined` if not provided)`.