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.

首先分析提议的 IShape、IShapeType 和 IShapeTSType 示例，以明确预期的泛型约束和继承语义。定义应接受哪些语法，并验证其在不改变 JavaScript 输出的情况下避免重复约束；该 issue 未指定任何实现文件或测试。