[Interpreter] Add support for loading from / storing to outer context variables.

test/cctest/compiler/c-signature.h

 // Copyright 2014 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_COMPILER_C_SIGNATURE_H_
 #define V8_COMPILER_C_SIGNATURE_H_
 
 #include "src/compiler/machine-type.h"
 
 namespace v8 {
@@ skipping 18 matching lines @@
 
 template <typename T>
 inline MachineType MachineTypeForC() {
   while (false) {
     // All other types T must be assignable to Object*
     *(static_cast<Object* volatile*>(0)) = static_cast<T>(0);
   }
   return kMachAnyTagged;
 }
 
+template <typename T>
+inline StoreRepresentation StoreRepresentationForC(
+    WriteBarrierKind write_barrier_kind) {
+  return StoreRepresentation(MachineTypeForC<T>(), write_barrier_kind);
+}
+
 #define DECLARE_TEMPLATE_SPECIALIZATION(ctype, mtype) \
   template <>                                         \
   inline MachineType MachineTypeForC<ctype>() {       \
     return mtype;                                     \
   }
 FOREACH_CTYPE_MACHINE_TYPE_MAPPING(DECLARE_TEMPLATE_SPECIALIZATION)
 #undef DECLARE_TEMPLATE_SPECIALIZATION
 
 // Helper for building machine signatures from C types.
 class CSignature : public MachineSignature {
@@ skipping 108 matching lines @@
 typedef CSignature2<int32_t, int32_t, int32_t> CSignature_i_ii;
 typedef CSignature2<uint32_t, uint32_t, uint32_t> CSignature_u_uu;
 typedef CSignature2<float, float, float> CSignature_f_ff;
 typedef CSignature2<double, double, double> CSignature_d_dd;
 typedef CSignature2<Object*, Object*, Object*> CSignature_o_oo;
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_C_SIGNATURE_H_