Generic Type constraint from base classes, interfaces (Pass through)

The ability to allow extends type constraint to be an abstract specification of base class, interface.
This also prevent duplication, by having to define the type constraint twice, reduces the need for unnecessary intermediate interfaces.

type ID = string

interface IShape<TID extends ID, Neasted>{
    __ID: TID;
    __Neasted : Neasted
}

interface ITSShape<T, ID>
{
    __tsType: T;
    __ID: ID;
}

interface IShapeType extends IShape<'T', boolean | number | null>
{
}

Not possible

interface IShapeTSType<T extends ['__Neasted']> extends IShapeType
{
    __tsType : T;
}


interface IShapeTSType<T extends ['__Neasted']> extends IShape<'T', boolean | number | string>
{
    __tsType : T;
}


interface IShapeTSType<T extends this['__Neasted']> extends IShapeType
{
    __tsType : T;
}

interface IShapeTSType<T extends TShape['__Neasted'], TShape extends IShapeType> extends TShape
{
    __tsType : T;
}

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

Comienza analizando los ejemplos propuestos de IShape, IShapeType e IShapeTSType para aclarar la semántica prevista de las restricciones genéricas y la herencia. Define qué sintaxis debería aceptarse y verifica que evita restricciones duplicadas sin cambiar la salida de JavaScript; el issue no menciona archivos de implementación ni pruebas.