Remove any2stringadd definition

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -351,7 +351,6 @@ class Definitions {
     @tu lazy val Predef_classOf  : Symbol = ScalaPredefModule.requiredMethod(nme.classOf)
     @tu lazy val Predef_identity : Symbol = ScalaPredefModule.requiredMethod(nme.identity)
     @tu lazy val Predef_undefined: Symbol = ScalaPredefModule.requiredMethod(nme.???)
-    @tu lazy val Predef_any2stringadd: Symbol = ScalaPredefModule.requiredMethod(nme.any2stringadd)
 
   def SubTypeClass(implicit ctx: Context): ClassSymbol = ctx.requiredClass("scala.<:<")