Make legacy tests a proper JUnit category

Author: nicolasstucki

compiler/test/dotc/LegacyTests.scala

@@ -0,0 +1,4 @@
+package dotc
+
+/** Legacy tests category for JUnit */
+trait LegacyTests

compiler/test/dotc/tests.scala

@@ -15,7 +15,7 @@ import scala.io.Source
  *  =======
  *  These are legacy, do not add tests here, see `CompilationTests.scala`
  */
-@Category(Array(classOf[java.lang.Exception]))
+@Category(Array(classOf[LegacyTests]))
 class tests extends CompilerTest {
 
   // tests that match regex '(pos|dotc|run|java|compileStdLib)\.*' would be

project/Build.scala

@@ -468,12 +468,12 @@ object Build {
 
       test in Test := {
         // Exclude legacy tests by default
-        (testOnly in Test).toTask(" -- --exclude-categories=java.lang.Exception,dotty.tools.dotc.SlowTests").value
+        (testOnly in Test).toTask(" -- --exclude-categories=dotc.LegacyTests,dotty.tools.dotc.SlowTests").value
       },
 
       testAll in Test := {
         // Exclude legacy tests by default
-        (testOnly in Test).toTask(" -- --exclude-categories=java.lang.Exception").value
+        (testOnly in Test).toTask(" -- --exclude-categories=dotc.LegacyTests").value
       },
 
       vulpix := Def.inputTaskDyn {