Feature request: wiring abstract classes and traits

The following does not compile:

object Foo {
  trait Dep
  abstract class Abs {
    def foo: Dep
  }
  trait T {
    def bar: Dep
  }

  val d: Dep = new Dep {}

  val a: Abs = wire[Abs]
  val t: T = wire[T]

  def main(args: Array[String]): Unit =
    println(s"a.foo ${a.foo}")
}

MacWire says

Error: class Abs is abstract; cannot be instantiated
  val a: Abs = wire[Abs]
Error: Cannot find a public constructor nor a companion object for [Foo.T]
  val t: T = wire[T]

It would be nice if macwire could wire abstract classes and traits when it can satisfy abstract members like it does for constructor args.

Start with the Scala reproduction in the issue and inspect how macwire currently handles constructor arguments, abstract classes, and traits. Define completion as making both wire[Abs] and wire[T] compile when their abstract members can be satisfied, while preserving the existing error behavior when they cannot.