fix #28988, remove throw on Dart1 incompatible is-checks for dartdevc

pkg/dev_compiler/test/browser/language_tests.js

Index: pkg/dev_compiler/test/browser/language_tests.js
diff --git a/pkg/dev_compiler/test/browser/language_tests.js b/pkg/dev_compiler/test/browser/language_tests.js
index b4078bc8d617d2cdfb65ca9ae030b71baba52cf8..8c8d8c86aea3332a616c928ad9b6321991e04de7 100644
--- a/pkg/dev_compiler/test/browser/language_tests.js
+++ b/pkg/dev_compiler/test/browser/language_tests.js
@@ -13,7 +13,6 @@ define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require',
   let mochaOnError = window.onerror;
   dart_sdk.dart.trapRuntimeErrors(false);
   dart_sdk.dart.ignoreWhitelistedErrors(false);
-  dart_sdk.dart.failForWeakModeIsChecks(false);
   dart_sdk._isolate_helper.startRootIsolate(function() {}, []);
   // Make it easier to debug test failures and required for formatter test that
   // assumes custom formatters are enabled.
@@ -82,6 +81,7 @@ define(['dart_sdk', 'async_helper', 'expect', 'unittest', 'is', 'require',
       'await_for_test': 'slow',
       'bit_operations_test_none_multi': fail,  // DDC/dart2js canonicalize bitop results to unsigned
       'branch_canonicalization_test': fail,  // JS bit operations truncate to 32 bits.
+      'call_test': fail,

[Jennifer Messerly, 2017/08/05 01:22:20]

this is just triage for another language test migration failure

       'call_closurization_test': fail, // Functions do not expose a "call" method.
       'canonical_const2_test': fail,
       'canonical_const_test': fail,