Change chiselCloneType and IO(...) to return parameterized type

chiselFrontend/src/main/scala/chisel3/core/Module.scala

@@ -217,7 +217,7 @@ abstract class BaseModule extends HasId {
    * TODO(twigg): Specifically walk the Data definition to call out which nodes
    * are problematic.
    */
-  protected def IO[T<:Data](iodef: T): iodef.type = {
+  protected def IO[T<:Data](iodef: T): T = {
     require(!_closed, "Can't add more ports after module close")
     requireIsChiselType(iodef, "io type")
 

src/main/scala/chisel3/compatibility.scala

@@ -42,10 +42,10 @@ package object Chisel {     // scalastyle:ignore package.object.name
       }
     }
   }
-  implicit class cloneTypeable[T<:Data](val target: T) extends AnyVal {
+  implicit class cloneTypeable[T <: Data](val target: T) extends AnyVal {
     import chisel3.core.DataMirror
-    def chiselCloneType: target.type = {
-      DataMirror.internal.chiselTypeClone(target).asInstanceOf[target.type]
+    def chiselCloneType: T = {
+      DataMirror.internal.chiselTypeClone(target).asInstanceOf[T]
     }
   }
 

src/main/scala/chisel3/package.scala

@@ -57,10 +57,10 @@ package object chisel3 {    // scalastyle:ignore package.object.name
     }
   }
 
-  implicit class cloneTypeable[T<:Data](val target: T) extends AnyVal {
+  implicit class cloneTypeable[T <: Data](val target: T) extends AnyVal {
     @deprecated("chiselCloneType is deprecated, use chiselTypeOf(...) to get the Chisel Type of a hardware object", "chisel3")
-    def chiselCloneType: target.type = {
-      target.cloneTypeFull.asInstanceOf[target.type]
+    def chiselCloneType: T = {
+      target.cloneTypeFull.asInstanceOf[T]
     }
   }