Enable classpath caching in test case

Author: allanrenucci

sbt-dotty/sbt-test/source-dependencies/binary/project/P.scala

@@ -5,10 +5,6 @@ object B extends Build
 {
 	lazy val dep = Project("dep", file("dep"))
 	lazy val use = Project("use", file("use")) settings(
-		unmanagedJars in Compile <+= packageBin in (dep, Compile) map Attributed.blank,
-
-    // Disable classpath caching since it does not invalidate modified jars
-    // (https://github.com/scala/bug/issues/10295)
-    scalacOptions += "-YdisableFlatCpCaching"
+		unmanagedJars in Compile <+= packageBin in (dep, Compile) map Attributed.blank
 	)
 }