JCTF testing: fix and extend --tool flag with 'r8cf' option.

Previous r8 and d8 options both ran the r8cf tests, too.

Change-Id: I2ad70046d385200370e77b93e64917dbbfbd8f64
diff --git a/build.gradle b/build.gradle
index f5a3337..cfaacdb 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1310,17 +1310,23 @@
         if (project.property('tool') == 'r8') {
             exclude "com/android/tools/r8/art/*/d8/**"
             exclude "com/android/tools/r8/jctf/d8/**"
-        } else {
-            assert(project.property('tool') == 'd8')
+            exclude "com/android/tools/r8/jctf/r8cf/**"
+        } else if (project.property('tool') == 'd8') {
             exclude "com/android/tools/r8/art/*/r8/**"
             exclude "com/android/tools/r8/jctf/r8/**"
+            exclude "com/android/tools/r8/jctf/r8cf/**"
+        } else {
+            assert(project.property('tool') == 'r8cf')
+            exclude "com/android/tools/r8/art/*/d8/**"
+            exclude "com/android/tools/r8/art/*/r8/**"
+            exclude "com/android/tools/r8/jctf/d8/**"
+            exclude "com/android/tools/r8/jctf/r8/**"
         }
     }
     if (!project.hasProperty('all_tests')) {
         exclude "com/android/tools/r8/art/dx/**"
         exclude "com/android/tools/r8/art/jack/**"
     }
-    // TODO(tamaskenez) enable jctf on all_tests when consolidated
     if (!project.hasProperty('jctf') && !project.hasProperty('only_jctf')) {
         exclude "com/android/tools/r8/jctf/**"
     }