test.py: Fixed incorrect handling of multitest in status files, status file cleanups.

dart/tests/lib/lib.status

Index: dart/tests/lib/lib.status
diff --git a/dart/tests/lib/lib.status b/dart/tests/lib/lib.status
index 0b555e3f5c166778317112c578c5b6172219f9d0..4a24e6e463954b29f2d24fac3b7173ba8b87f9c8 100644
--- a/dart/tests/lib/lib.status
+++ b/dart/tests/lib/lib.status
@@ -84,9 +84,9 @@ json/json_test: Fail                            # Issue 10961
 
 [ $runtime == ff ]
 # FF setTimeout can fire early: https://bugzilla.mozilla.org/show_bug.cgi?id=291386
-multiple_timer_test: Pass, Fail
-timer_isolate_test: Pass, Fail
-timer_test: Pass, Fail
+async/multiple_timer_test: Pass, Fail
+async/timer_isolate_test: Pass, Fail
+async/timer_test: Pass, Fail
 convert/chunked_conversion_utf88_test: Pass, Timeout  # Issue 12029
 convert/streamed_conversion_utf8_encode_test: Pass, Timeout  # Issue 12029
 convert/streamed_conversion_utf8_decode_test: Pass, Slow  # Issue 12029
@@ -137,8 +137,8 @@ convert/streamed_conversion_json_utf8_decode_test: Pass, Slow
 convert/chunked_conversion_utf88_test: Pass, Slow # Issue 12644.
 
 [ $compiler == none && $runtime == drt ]
-run_zoned6_test/01: fail # Issue 12756.
-run_zoned9_test/01: fail # Issue 12756.
+async/run_zoned6_test/01: fail # Issue 12756.
+async/run_zoned9_test/01: fail # Issue 12756.
 
 [ $compiler == dartanalyzer ]
-library_metadata2_test/01: Fail # http://dartbug.com/12950
+mirrors/library_metadata2_test/01: Fail # http://dartbug.com/12950