add check file prefix for hyperdsl

Author: TiarkRompf

test-src/epfl/test12-collections/TestArrayOps.scala

@@ -7,7 +7,7 @@ import java.io.PrintWriter
 
 class TestArrayOps extends FileDiffSuite {
 
-  val prefix = "test-out/epfl/test12-"
+  val prefix = home + "test-out/epfl/test12-"
 
   def testIntArrayCreation() {
     withOutFile(prefix+"array-seq-creation") {

test-src/epfl/test14-scratch/TestDataOp.scala

@@ -13,7 +13,7 @@ import java.io.{PrintWriter,StringWriter,FileOutputStream}
 
 class TestDataOp extends FileDiffSuite {
 
-  val prefix = "test-out/epfl/test14-"
+  val prefix = home + "test-out/epfl/test14-"
 
   trait DSL extends ScalaOpsPkg with TupledFunctions with UncheckedOps with LiftPrimitives with LiftString with LiftVariables {
     // keep track of top level functions

test-src/epfl/test14-scratch/TestQueries.scala

@@ -890,7 +890,7 @@ trait Util {
 // test cases
 class TestQueries extends FileDiffSuite {
 
-  val prefix = "test-out/epfl/test14-"
+  val prefix = home + "test-out/epfl/test14-"
 
   trait DSL extends Staged with Compile {
     def test(): Unit