source-dependencies/value-class-underlying: fix test

We were not testing what we thought we were testing before, because C
used the name "x" which is also the name of the parameter we change in
A, so when we changed A we were invalidating C too. Fixed by using a
different name than "x" in C, which reveals that there is a bug
somewhere since the test doesn't pass anymore.

project/Scripted.scala

@@ -75,6 +75,7 @@ object Scripted {
                  bufferLog: Boolean,
                  prescripted: File => Unit): Unit = {
     System.err.println(s"About to run tests: ${args.mkString("\n * ", "\n * ", "\n")}")
+    sys.props(org.apache.logging.log4j.util.LoaderUtil.IGNORE_TCCL_PROPERTY) = "true"
     val noJLine = new classpath.FilteredLoader(scriptedSbtInstance.loader, "jline." :: Nil)
     val loader = classpath.ClasspathUtilities.toLoader(scriptedSbtClasspath.files, noJLine)
     val bridgeClass = Class.forName("sbt.internal.inc.IncScriptedRunner", true, loader)

zinc/src/sbt-test/source-dependencies/value-class-underlying/C.scala

@@ -1,6 +1,6 @@
 object C {
   def main(args: Array[String]): Unit = {
-    val x = B.foo
-    println("x: " + x) // Need to use x in an expression to see if it crashes or not
+    val duck = B.foo
+    println("duck: " + duck) // Need to use duck in an expression to see if it crashes or not
   }
 }