Merge pull request #9448 from dwijnand/names-ThisNameType

Drop the "Name with" in Name's ThisNameType

src/reflect/scala/reflect/internal/Names.scala

@@ -201,15 +201,11 @@ trait Names extends api.Names {
     type ThisNameType >: Null <: Name
     protected[this] def thisName: ThisNameType
 
-    // Note that "Name with ThisNameType" should be redundant
-    // because ThisNameType <: Name, but due to scala/bug#6161 the
-    // compile loses track of this fact.
-
     /** Index into name table */
     final def start: Int = index
 
     /** The next name in the same hash bucket. */
-    def next: Name with ThisNameType
+    def next: ThisNameType
 
     /** The length of this name. */
     final def length: Int = len
@@ -228,14 +224,15 @@ trait Names extends api.Names {
       (if (other.isTermName) toTermName else toTypeName).asInstanceOf[N]
 
     /** Return the subname with characters from from to to-1. */
-    def subName(from: Int, to: Int): Name with ThisNameType
+    def subName(from: Int, to: Int): ThisNameType
+
     override def subSequence(from: Int, to: Int): CharSequence = subName(from, to)
 
     /** Return a new name of the same variety. */
-    def newName(str: String): Name with ThisNameType
+    def newName(str: String): ThisNameType
 
     /** Return a new name based on string transformation. */
-    def mapName(f: String => String): Name with ThisNameType = newName(f(toString))
+    def mapName(f: String => String): ThisNameType = newName(f(toString))
 
     /** Copy bytes of this name to buffer cs, starting at position `offset`. */
     final def copyChars(cs: Array[Char], offset: Int) =