Fix source position for stack traces with optimized top function.

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/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 672 matching lines @@
         // TODO(fschneider): Add support for other array types.
         UNREACHABLE();
     }
     AssertAssignableInstr* assert_value =
         new AssertAssignableInstr(call->token_pos(),
                                   value->Copy(),
                                   instantiator,
                                   type_args,
                                   value_type,
                                   Symbols::Value());
-    InsertBefore(call, assert_value, NULL, Definition::kValue);
+    // Newly inserted instructions that can deoptimize or throw an exception
+    // must have a deoptimization id that is valid for lookup in the unoptimized
+    // code.
+    assert_value->deopt_id_ = call->deopt_id();
+    InsertBefore(call, assert_value, call->env(), Definition::kValue);
   }
 
   Value* array = NULL;
   Value* index = NULL;
   intptr_t array_cid = PrepareIndexedOp(call, class_id, &array, &index);
   Value* value = call->ArgumentAt(2)->value();
   // Check if store barrier is needed.
   bool needs_store_barrier = true;
   if (!value_check.IsNull()) {
     needs_store_barrier = false;
@@ skipping 3892 matching lines @@
 
   if (FLAG_trace_constant_propagation) {
     OS::Print("\n==== After constant propagation ====\n");
     FlowGraphPrinter printer(*graph_);
     printer.PrintBlocks();
   }
 }
 
 
 }  // namespace dart