Implement rewind: drop one or more frames from the debugger.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/bootstrap.h"
 #include "vm/compiler.h"
 #include "vm/constant_propagator.h"
@@ skipping 3057 matching lines @@
       compiler->GenerateInstanceCall(deopt_id(), token_pos(), ArgumentCount(),
                                      locs(), unary_ic_data);
     } else {
       // Call was not visited yet, use original ICData in order to populate it.
       compiler->GenerateInstanceCall(deopt_id(), token_pos(), ArgumentCount(),
                                      locs(), *call_ic_data);
     }
   } else {
     // Unoptimized code.
     ASSERT(!HasICData());
+    compiler->AddCurrentDescriptor(RawPcDescriptors::kRewind, deopt_id(),
+                                   token_pos());
     bool is_smi_two_args_op = false;
     const StubEntry* stub_entry = TwoArgsSmiOpInlineCacheEntry(token_kind());
     if (stub_entry != NULL) {
       // We have a dedicated inline cache stub for this operation, add an
       // an initial Smi/Smi check with count 0.
       is_smi_two_args_op = call_ic_data->AddSmiSmiCheckForFastSmiStubs();
     }
     if (is_smi_two_args_op) {
       ASSERT(ArgumentCount() == 2);
       compiler->EmitInstanceCall(*stub_entry, *call_ic_data, ArgumentCount(),
@@ skipping 841 matching lines @@
   set_native_c_function(native_function);
   function().SetIsNativeAutoSetupScope(auto_setup_scope);
   Dart_NativeEntryResolver resolver = library.native_entry_resolver();
   bool is_bootstrap_native = Bootstrap::IsBootstapResolver(resolver);
   set_is_bootstrap_native(is_bootstrap_native);
 }
 
 #undef __
 
 }  // namespace dart