spec for ParameterProperties is outdated

[ajafff]

https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md#831-constructor-parameters:

A parameter of a ConstructorImplementation may be prefixed with a public, private, or protected modifier.

This is missing readonly.

A parameter property declaration may declare an optional parameter (by including a question mark or a default value), but the property introduced by such a declaration is always considered a required property

This is no longer true since the (not so) recent rewrite of the declaration emitter.

[MartinJohns]

The entire spec is outdated. The last real comit on it was nearly three years ago: https://github.com/Microsoft/TypeScript/commits/master/doc/spec.md

See also: https://github.com/Microsoft/TypeScript/issues?q=is%3Aopen+is%3Aissue+label%3ASpec
And mainly: #15711

[RyanCavanaugh]

The spec is now an "archived" artifact and we won't be tracking defects against it anymore.