drop unused bitfield comment

src/main/scala/com/htmlism/mos6502/dsl/BitField.scala

@@ -14,9 +14,4 @@ trait BitField[A] {
     * ASM-safe label
     */
   def label(x: A): String
-
-  /**
-    * Comment string
-    */
-  def comment(x: A): String
 }

src/test/scala/com/htmlism/mos6502/dsl/DslSpec.scala

@@ -188,9 +188,6 @@ object TestDirection {
 
       def label(x: TestDirection): String =
         x.toString.toLowerCase
-
-      def comment(x: TestDirection): String =
-        x.toString
     }
 
   implicit val mappingDirection: Mapping[TestDirection] =

src/test/scala/com/htmlism/mos6502/dsl/snake/Direction.scala

@@ -14,9 +14,6 @@ object Direction {
 
       def label(x: Direction): String =
         "moving" + x.toString
-
-      def comment(x: Direction): String =
-        x.toString
     }
 }