run/classfile-format-52.scala, run on java8, needs -target:jvm-1.8

Author: adriaanm

test/files/run/classfile-format-52.scala

@@ -14,7 +14,7 @@ import Opcodes._
 // By its nature the test can only work on JDK 8+ because under JDK 7- the
 // interface won't verify.
 object Test extends DirectTest {
-  override def extraSettings: String = "-optimise -usejavacp -d " + testOutput.path + " -cp " + testOutput.path
+  override def extraSettings: String = "-target:jvm-1.8 -optimise -usejavacp -d " + testOutput.path + " -cp " + testOutput.path
 
   def generateInterface() {
     val interfaceName =  "HasDefaultMethod"