When tracing type checks in runtime, also print the method where the type check occured.

runtime/vm/code_generator.cc

 // Copyright (c) 2011, 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/code_generator.h"
 
 #include "vm/code_index_table.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/dart_api_impl.h"
@@ skipping 324 matching lines @@
     } else {
       // Instantiate type before printing.
       const AbstractType& instantiated_type =
           AbstractType::Handle(type.InstantiateFrom(type_instantiator));
       OS::Print("InstanceOf: '%s' %s '%s' instantiated from '%s'.\n",
                 String::Handle(instance_type.Name()).ToCString(),
                 (result.raw() == Bool::True()) ? "is" : "is !",
                 String::Handle(instantiated_type.Name()).ToCString(),
                 String::Handle(type.Name()).ToCString());
     }
+    DartFrameIterator iterator;
+    DartFrame* caller_frame = iterator.NextFrame();
+    ASSERT(caller_frame != NULL);
+    const Function& function = Function::Handle(
+        caller_frame->LookupDartFunction());
+    OS::Print(" -> Function %s\n", function.ToFullyQualifiedCString());
   }
   arguments.SetReturn(result);
 }
 
 
 DEFINE_RUNTIME_ENTRY(Throw, 1) {
   ASSERT(arguments.Count() == kThrowRuntimeEntry.argument_count());
   const Instance& exception = Instance::CheckedHandle(arguments.At(0));
   Exceptions::Throw(exception);
 }
@@ skipping 763 matching lines @@
       }
     }
   }
   // The cache is null terminated, therefore the loop above should never
   // terminate by itself.
   UNREACHABLE();
   return Code::null();
 }
 
 }  // namespace dart