Unfold yet another use of bounds case class

We save one `map`, and may avoid creating a lot of unused `TypeBounds`
objects that are later discarded.

Author: diesalbla

src/reflect/scala/reflect/internal/tpe/GlbLubs.scala

@@ -328,10 +328,12 @@ private[internal] trait GlbLubs {
               else if (symtypes.tail forall (symtypes.head =:= _))
                 proto.cloneSymbol(lubRefined.typeSymbol).setInfoOwnerAdjusted(symtypes.head)
               else {
-                def lubBounds(bnds: List[TypeBounds]): TypeBounds =
-                  TypeBounds(glb(bnds map (_.lo), depth.decr), lub(bnds map (_.hi), depth.decr))
+                val lubBs = TypeBounds(
+                  glb(symtypes.map(_.lowerBound), depth.decr),
+                  lub(symtypes.map(_.upperBound), depth.decr)
+                )
                 lubRefined.typeSymbol.newAbstractType(proto.name.toTypeName, proto.pos)
-                  .setInfoOwnerAdjusted(lubBounds(symtypes map (_.bounds)))
+                  .setInfoOwnerAdjusted(lubBs)
               }
             }
           }