Introduce intrinsic to expose debug state to generated code.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include "src/v8.h"
 
 #include "src/allocation.h"
@@ skipping 6097 matching lines @@
 
   static HObjectAccess ForAllocationMementoSite() {
     return HObjectAccess(kInobject, AllocationMemento::kAllocationSiteOffset);
   }
 
   static HObjectAccess ForCounter() {
     return HObjectAccess(kExternalMemory, 0, Representation::Integer32(),
                          Handle<String>::null(), false, false);
   }
 
+  static HObjectAccess ForExternalUInteger8() {
+    return HObjectAccess(kExternalMemory, 0, Representation::UInteger8(),
+                         Handle<String>::null(), false, false);
+  }
+
   // Create an access to an offset in a fixed array header.
   static HObjectAccess ForFixedArrayHeader(int offset);
 
   // Create an access to an in-object property in a JSObject.
   // This kind of access must be used when the object |map| is known and
   // in-object properties are being accessed. Accesses of the in-object
   // properties can have different semantics depending on whether corresponding
   // property was added to the map or not.
   static HObjectAccess ForMapAndOffset(Handle<Map> map, int offset,
       Representation representation = Representation::Tagged());
@@ skipping 1674 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_