Add data-URI support class to dart:core (next to Uri).

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
@@ skipping 159 matching lines @@
   ASSERT(call->HasICData());
   if (call->ic_data()->NumberOfUsedChecks() > 0) {
     // This occurs when an instance call has too many checks, will be converted
     // to megamorphic call.
     return false;
   }
   if (FLAG_warn_on_javascript_compatibility) {
     // Do not make the instance call megamorphic if the callee needs to decode
     // the calling code sequence to lookup the ic data and verify if a warning
     // has already been issued or not.
-    // TryCreateICData is only invoked if the ic_data target has not been called
-    // yet, so no warning can possibly have been issued.
-    ASSERT(!call->ic_data()->IssuedJSWarning());

[Lasse Reichstein Nielsen, 2015/11/12 11:48:25]

This was hit by standalone/javascript_compatibility_test/{20,21,50,51} - unless
the optimization threshold was raised from 5 to 7 in that test.

[Florian Schneider, 2015/11/12 11:51:10]

The reason you hit this is because the string interpolation function is now
optimized earlier. 

The assert is not valid -- a call that throws a JS compatibility warning error
may have empty IC data, but the IssuedJSWarning flag set.

     if (call->ic_data()->MayCheckForJSWarning()) {
       return false;
     }
   }
   GrowableArray<intptr_t> class_ids(call->ic_data()->NumArgsTested());
   ASSERT(call->ic_data()->NumArgsTested() <= call->ArgumentCount());
   for (intptr_t i = 0; i < call->ic_data()->NumArgsTested(); i++) {
     class_ids.Add(call->PushArgumentAt(i)->value()->Type()->ToCid());
   }
 
@@ skipping 8592 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart