Disabled code that caused duplicate definition crasher.

Two overriding lazyvals cause a duplicate definition in the getter.
Now DottyBackendInterface compiles up to backend, where it dies
with

	at scala.Predef$.assert(Predef.scala:151)
	at dotty.tools.dotc.core.Types$MethodType.<init>(Types.scala:1963)
	at dotty.tools.dotc.core.Types$CachedMethodType.<init>(Types.scala:2057)
	at dotty.tools.dotc.core.Types$MethodType$.apply(Types.scala:2104)
	at dotty.tools.dotc.core.Types$MethodType$.apply(Types.scala:2102)
	at dotty.tools.dotc.core.Types$MethodTypeCompanion.apply(Types.scala:2080)
	at dotty.tools.dotc.core.TypeErasure.eraseInfo(TypeErasure.scala:384)
	at dotty.tools.dotc.core.TypeErasure$.transformInfo(TypeErasure.scala:165)
	at dotty.tools.dotc.transform.Erasure.transform(Erasure.scala:54)
	at dotty.tools.dotc.core.Denotations$SingleDenotation.current(Denotations.scala:568)
	at dotty.tools.dotc.core.Symbols$Symbol.denot(Symbols.scala:394)
	at dotty.tools.dotc.core.Symbols$Symbol.name(Symbols.scala:462)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation$$anonfun$computeMemberNames$1$2.apply(SymDenotations.scala:1549)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation$$anonfun$computeMemberNames$1$2.apply(SymDenotations.scala:1549)
	at scala.collection.Iterator$class.foreach(Iterator.scala:750)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:1202)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation.computeMemberNames$1(SymDenotations.scala:1549)
	at dotty.tools.dotc.core.SymDenotations$ClassDenotation.memberNames(SymDenotations.scala:1558)
	at dotty.tools.dotc.core.Types$Type.memberNames(Types.scala:510)
	at dotty.tools.dotc.core.Types$Type.memberDenots(Types.scala:526)
	at dotty.tools.dotc.core.Types$Type$$anonfun$memberClasses$1.apply(Types.scala:557)
	at dotty.tools.dotc.core.Types$Type$$anonfun$memberClasses$1.apply(Types.scala:557)
	at dotty.tools.dotc.util.Stats$.track(Stats.scala:35)
	at dotty.tools.dotc.core.Types$Type.memberClasses(Types.scala:556)
	at dotty.tools.backend.jvm.DottyBackendInterface$$anon$9.memberClasses(DottyBackendInterface.scala:691)

Author: odersky

src/dotty/tools/backend/jvm/DottyBackendInterface.scala

@@ -103,8 +103,9 @@ class DottyBackendInterface()(implicit ctx: Context) extends BackendInterface{
   val BoxesRunTimeClass      = toDenot(BoxesRunTimeModule).moduleClass.asClass
 
    // require LambdaMetafactory: scalac uses getClassIfDefined, but we need those always.
-  override lazy val LambdaMetaFactory = ctx.requiredClass("java.lang.invoke.LambdaMetafactory")
-  override lazy val MethodHandle      = ctx.requiredClass("java.lang.invoke.MethodHandle")
+  // disabled, because it causes crashes (duplicate definition)
+  //override lazy val LambdaMetaFactory = ctx.requiredClass("java.lang.invoke.LambdaMetafactory")
+  //override lazy val MethodHandle      = ctx.requiredClass("java.lang.invoke.MethodHandle")
 
   val nme_valueOf: Name = StdNames.nme.valueOf
   val nme_apply = StdNames.nme.apply