regression in xml lib

[scabug]

Worked in 2.9.

scala> new xml.Elem(null, null, xml.Null, xml.TopScope, Nil: _*)
<console>:8: error: ambiguous reference to overloaded definition,
both constructor Elem in class Elem of type (prefix: String, label: String, attributes: scala.xml.MetaData, scope: scala.xml.NamespaceBinding, child: scala.xml.Node*)scala.xml.Elem
and  constructor Elem in class Elem of type (prefix: String, label: String, attributes1: scala.xml.MetaData, scope: scala.xml.NamespaceBinding, minimizeEmpty: Boolean, child: scala.xml.Node*)scala.xml.Elem
match argument types (Null,Null,xml.Null.type,xml.TopScope.type,Nothing)
              new xml.Elem(null, null, xml.Null, xml.TopScope, Nil: _*)
              ^

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-5858?orig=1
Reporter: @paulp
Affected Versions: 2.10.0
See #5859

[scabug]

@som-snytt said:
See #1118
but this works

xmlover.scala:10: warning: constructor Elem in class Elem is deprecated: This constructor is retained for backward compatibility. Please use the primary constructor, which lets you specify your own preference for `minimizeEmpty`.
    val y = new xml.Elem(null, null, xml.Null, xml.TopScope, (Nil: Seq[Node]): _*)

"But that's a Boolean param!"

I really am rushing off to pick up at pre-K, that's not just an exit line.

[scabug]

@retronym said:
Fixed by #5859; closing with a test case: scala/scala#1731

[scabug]

@adriaanm said:
reopening for 2.10.1-RC1 backport