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

runtime/vm/code_generator.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/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 2197 matching lines @@
 
   // Return value tells deoptimization stub to remove the given number of bytes
   // from the stack.
   arguments.SetReturn(Smi::Handle(Smi::New(deopt_arg_count * kWordSize)));
 #else
   UNREACHABLE();
 #endif  // !DART_PRECOMPILED_RUNTIME
 }
 
 
+DEFINE_RUNTIME_ENTRY(RewindPostDeopt, 0) {
+#if !defined(DART_PRECOMPILED_RUNTIME)
+  isolate->debugger()->RewindPostDeopt();
+#else
+  UNREACHABLE();
+#endif  // !DART_PRECOMPILED_RUNTIME
+}
+
 DEFINE_LEAF_RUNTIME_ENTRY(intptr_t,
                           BigintCompare,
                           2,
                           RawBigint* left,
                           RawBigint* right) {
   Thread* thread = Thread::Current();
   StackZone zone(thread);
   HANDLESCOPE(thread);
   const Bigint& big_left = Bigint::Handle(left);
   const Bigint& big_right = Bigint::Handle(right);
@@ skipping 54 matching lines @@
   const intptr_t elm_size = old_data.ElementSizeInBytes();
   const TypedData& new_data =
       TypedData::Handle(TypedData::New(cid, new_size, Heap::kOld));
   TypedData::Copy(new_data, 0, old_data, 0, old_size * elm_size);
   typed_data_cell.SetAt(0, new_data);
   arguments.SetReturn(new_data);
 }
 
 
 }  // namespace dart