This way, we have only one implementation for all the versions ofScala. This will become more useful as we make its implementationless trivial.We also rename it back to `UniquenessCache`, which is the name ithas on the JVM, and reinstate the `Null` lower bound on `V`. Therewas no reason to name it differently, and keeping the name may bebetter for binary compatibility (even though it is `private[scala]`and nobody should be using it). It is still different for the keytype, which is fixed to `String`.

They were changed in757949e touse a `js.WrappedArray` by default, instead of an `ArrayBuffer`.Unfortunately, if we want to make the scalalib independent from theScala.js library, this is not something we can do anymore.Ideally, we would override `ArrayBuffer` itself with animplementation based on `js.Array`. We cannot do that eitherbecause its `array` field is protected, and it is not final.

It has specific overrides in `overrides-2.12` and `overrides-2.13`.

…obal`.This is required not to depend on the Scala.js library from`ExecutionContext`.

This removes references to run-time components of`js.WrappedDictionary` that the IR cleaner cannot get rid of.

We use it in the scalalib, so that we do not generate referencesto `toScalaVarArgs`, which uses custom collections from theScala.js library.

It is configured differently than for the javalib. We allowreferences to `scala.*` (obviously) but disallow references to`scala.scalajs.*`. We also avoid rewriting Scala functions to JSfunctions, since that changes the binary APIs.We use a local copy of `sjs.runtime.AnonFunctionN` classes in`scala.runtime.*` to support the codegen of lambdas.