Remove outdated tests.

dotc_core_transform directory is empty. Files where moved while restructuring erasure.

Author: DarkDimius

test/dotc/tests.scala

@@ -108,8 +108,6 @@ class tests extends CompilerTest {
       defaultOptions diff List("-YnoDeepSubtypes"))
   // @odesky, fails on assertion in TypeComparer:425 (fixed)
 
-  @Test def dotc_core_transform = compileDir(dotcDir + "tools/dotc/core/transform", twice)
-
   @Test def dotc_transform = compileDir(dotcDir + "tools/dotc/transform", twice)
   // @odersky, fails with datarace (fixed)
   // now fails with unapplied setter generated by pattern matcher: