Moved Milli._ to IO.

util-cache/src/main/scala/sbt/util/FileInfo.scala

@@ -8,7 +8,7 @@ import scala.util.control.NonFatal
 import sbt.io.Hash
 import sjsonnew.{ Builder, JsonFormat, Unbuilder, deserializationError }
 import CacheImplicits._
-import sbt.io.Milli.getModifiedTime
+import sbt.io.IO.getModifiedTime
 
 sealed trait FileInfo { def file: File }
 sealed trait HashFileInfo extends FileInfo { def hash: List[Byte] }

util-cache/src/test/scala/FileInfoSpec.scala

@@ -3,7 +3,7 @@ package sbt.util
 import sjsonnew.shaded.scalajson.ast.unsafe._
 import sjsonnew._, support.scalajson.unsafe._
 import sbt.internal.util.UnitSpec
-import sbt.io.Milli.getModifiedTime
+import sbt.io.IO.getModifiedTime
 
 class FileInfoSpec extends UnitSpec {
   val file = new java.io.File(".").getAbsoluteFile