Remove the debugger_ field from Isolate in a PRODUCT build

runtime/vm/kernel_to_il.cc

 // Copyright (c) 2016, 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 <set>
 
 #include "vm/kernel_to_il.h"
 
 #include "vm/compiler.h"
 #include "vm/intermediate_language.h"
@@ skipping 1832 matching lines @@
     if (dst_type.IsMalformed()) {
       return ThrowTypeError();
     }
     return CheckAssignableInCheckedMode(dst_type, name_symbol);
   }
   return Fragment();
 }
 
 bool FlowGraphBuilder::NeedsDebugStepCheck(const Function& function,
                                            TokenPosition position) {
-  return FLAG_support_debugger && position.IsDebugPause() &&
-         !function.is_native() && function.is_debuggable();
+  return position.IsDebugPause() && !function.is_native() &&
+         function.is_debuggable();
 }
 
 bool FlowGraphBuilder::NeedsDebugStepCheck(Value* value,
                                            TokenPosition position) {
-  if (!FLAG_support_debugger || !position.IsDebugPause()) return false;
+  if (!position.IsDebugPause()) {
+    return false;
+  }
   Definition* definition = value->definition();
-  if (definition->IsConstant() || definition->IsLoadStaticField()) return true;
+  if (definition->IsConstant() || definition->IsLoadStaticField()) {
+    return true;
+  }
   if (definition->IsAllocateObject()) {
     return !definition->AsAllocateObject()->closure_function().IsNull();
   }
   return definition->IsLoadLocal() &&
          !definition->AsLoadLocal()->local().IsInternal();
 }
 
 Fragment FlowGraphBuilder::DebugStepCheck(TokenPosition position) {
   return Fragment(new (Z) DebugStepCheckInstr(
       position, RawPcDescriptors::kRuntimeCall, GetNextDeoptId()));
@@ skipping 465 matching lines @@
   StreamingFlowGraphBuilder streaming_flow_graph_builder(
       &helper, zone_, script.kernel_data(), script.kernel_data_size());
   return streaming_flow_graph_builder.GetLineStartsFor(
       script.kernel_script_index());
 }
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)