Java 8 override restrictions: interface can't implement a method of 'Any'

- update Range and related classes

generators/src/org/jetbrains/kotlin/generators/builtins/ranges.kt

@@ -62,6 +62,8 @@ class GenerateRanges(out: PrintWriter) : BuiltInsSourceGenerator(out) {
                 "    }"
             }
 
+            val toString = "\"\$start..\$end\""
+
             out.println(
 """/**
  * A range of values of type `$t`.
@@ -82,6 +84,8 @@ public class $range(override val start: $t, override val end: $t) : Range<$t>, P
 
     override fun hashCode(): Int $hashCode
 
+    override fun toString(): String = $toString
+
     companion object {
         /** An empty range of values of type $t. */
         public val EMPTY: $range = $range($emptyBounds)