Skip spurious constants in deferred computation.

tests/compiler/dart2js_extra/dart2js_extra.status

Index: tests/compiler/dart2js_extra/dart2js_extra.status
diff --git a/tests/compiler/dart2js_extra/dart2js_extra.status b/tests/compiler/dart2js_extra/dart2js_extra.status
index bde5681180b01593e607fc728a525eaf15900094..897d5b3bd52e4f2644180f180af3b7e1bbddfa8c 100644
--- a/tests/compiler/dart2js_extra/dart2js_extra.status
+++ b/tests/compiler/dart2js_extra/dart2js_extra.status
@@ -53,7 +53,7 @@ timer_negative_test: Fail, OK # A negative runtime test.
 bailout8_test: Fail, OK # Mismatch in thrown exception.
 
 [ $compiler == dart2js && $runtime == d8 && $system == windows ]
-deferred/*: Skip # Issue 17458
+deferred/*: Pass,RuntimeError # Issue 17458

[Siggi Cherem (dart-lang), 2016/05/09 20:03:04]

Are these actually flaky? Can we just do "RuntimeError" or maybe use
"SkipByDesign"? Looking at the bug, it seems this is not supported at this time?

[Johnni Winther, 2016/05/10 09:26:16]

d8 on Windows doesn't support the properties we use to tell where the script is
located. For that reason, some deferred tests (the positive ones) fail at
runtime, whereas some deferred tests (the negative ones) might not fail or are
expected to fail.

To give better coverage on Windows we still compile the tests (checking
invariants and such) but don't expect to much of the runtime.

[Siggi Cherem (dart-lang), 2016/05/10 16:59:09]

I see. Two suggestions then:
 - label each test individually: that way each test is either Pass or
RuntimeError, but not both. It's my understanding that the way it is currently
written marks every test as flaky and will make our test infrastructure waste
time retrying the tests a couple times.

 - whenever we have a `RuntimeError`, write in the comment that this at least
expects no `CompileTimeError`.

 
 [ $compiler == dart2js && $csp ]
 deferred_fail_and_retry_test: SkipByDesign # Uses eval to simulate failed loading.