Stop emitting "overrides" in the respecting language idiomatic way for
static methods and properties (while ES6 supports those, this is not
true of Java and C#).

In Java, this is mostly getting rid of `@Overrides` on static
declarations. C# *allows* (but does not require) explicitly hiding the
parent declaration using the `new` keyword. This was introduced as it
provides additional safeguards against our generating incorrect code.

Fixes #2358