DBC: Fleshing out the polymorphic instance call instruction

runtime/vm/flow_graph_compiler.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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
@@ skipping 972 matching lines @@
   return stub->entry_label();
 }
 
 
 #if defined(TARGET_ARCH_DBC)
 void FlowGraphCompiler::EmitDeopt(intptr_t deopt_id,
                                   ICData::DeoptReasonId reason,
                                   uint32_t flags) {
   ASSERT(is_optimizing());
   ASSERT(!intrinsic_mode());
+  // The pending deoptimization environment may be changed after this deopt is
+  // emitted, so we need to make a copy.
+  Environment* env_copy =
+      pending_deoptimization_env_->DeepCopy(zone());
   CompilerDeoptInfo* info =
       new(zone()) CompilerDeoptInfo(deopt_id,
                                     reason,
                                     flags,
-                                    pending_deoptimization_env_);
-
+                                    env_copy);
   deopt_infos_.Add(info);
   assembler()->Deopt(0, /*is_eager =*/ 1);
   info->set_pc_offset(assembler()->CodeSize());
 }
 #endif  // defined(TARGET_ARCH_DBC)
 
 
 void FlowGraphCompiler::FinalizeExceptionHandlers(const Code& code) {
   ASSERT(exception_handlers_list_ != NULL);
   const ExceptionHandlers& handlers = ExceptionHandlers::Handle(
@@ skipping 986 matching lines @@
 
 
 void FlowGraphCompiler::FrameStateClear() {
   ASSERT(!is_optimizing());
   frame_state_.TruncateTo(0);
 }
 #endif  // defined(DEBUG) && !defined(TARGET_ARCH_DBC)
 
 
 }  // namespace dart