Record Scala package object as provided name (Cherry-pick of #15582)

[stuhood]

The package object should also be recorded as provided name, as it also behaves as an object.

An example that will fail without this fix:

File t.scala:

package object example {
   trait T[A]
}

File a.scala:

package example

package object a {
   implicit val tString: T[String] = new T[String] {}
}

File b.scala:

package example.b

import example.T
import example.a._

object B {
   val x = implicitly[T[String]]
}