Operator overloading with primitive syntax

[sirisian]

https://github.com/sirisian/ecmascript-types/blob/master/README.md#classes-and-operator-overloading
https://github.com/sirisian/ecmascript-types/blob/master/primitivemetadata.md
tc39/proposal-operator-overloading#29

The primitive metadata extension defines syntax for primitive operator blocks.

In the now withdrawn operator overloading proposal I made an issue with the syntax:

// Extension operators for Vector2
class Number {
  operator*(v:Vector2) {
    return v * s;
  }
}

// Extension operators for Matrix4x4
class Number {
  operator*(v:Matrix4x4) {
    return v * s;
  }
}

with the primitive metadata operators it now looks like:

primitive number {
  operator*(v: Vector2) {
    return v * this;
  }
}

primitive number {
  operator*(m: Matrix4x4) {
    return m * this;
  }
}

Might move this to another markdown file as I want to include more examples.