Dotty: actually put dotty.jar into bootclasspath.

Partest used to run tests with Dotty, but stopped at some moment.
I guess this line may have been deleted at some merge conflict.

Author: DarkDimius

project/Build.scala

@@ -110,7 +110,7 @@ object DottyBuild extends Build {
         path = file.getAbsolutePath
       } yield "-Xbootclasspath/p:" + path
       // dotty itself needs to be in the bootclasspath
-      val fullpath = ("-Xbootclasspath/a:" + bin) :: path.toList
+      val fullpath = ("-Xbootclasspath/p:" + "dotty.jar") :: ("-Xbootclasspath/a:" + bin) :: path.toList
       // System.err.println("BOOTPATH: " + fullpath)
 
       val travis_build = // propagate if this is a travis build