Move code for accessing captured variables into the IL.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 7672)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -53,6 +53,7 @@
   M(AllocateObject, AllocateObjectComp)                                        \
   M(AllocateObjectWithBoundsCheck, AllocateObjectWithBoundsCheckComp)          \
   M(NativeLoadField, NativeLoadFieldComp)                                      \
+  M(NativeStoreField, NativeStoreFieldComp)                                    \
   M(InstantiateTypeArguments, InstantiateTypeArgumentsComp)                    \
   M(ExtractConstructorTypeArguments, ExtractConstructorTypeArgumentsComp)      \
   M(ExtractConstructorInstantiator, ExtractConstructorInstantiatorComp)        \
@@ -928,12 +929,34 @@
   intptr_t offset_in_bytes() const { return offset_in_bytes_; }
 
  private:
-  intptr_t offset_in_bytes_;
+  const intptr_t offset_in_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeLoadFieldComp);
 };
 
 
+class NativeStoreFieldComp : public TemplateComputation<2> {
+ public:
+  NativeStoreFieldComp(Value* dest, intptr_t offset_in_bytes, Value* value)
+      : offset_in_bytes_(offset_in_bytes) {
+    ASSERT(value != NULL);
+    inputs_[0] = dest;
+    inputs_[1] = value;
+  }
+
+  DECLARE_COMPUTATION(NativeStoreField)
+
+  Value* dest() { return inputs_[0]; }
+  Value* value() { return inputs_[1]; }
+  intptr_t offset_in_bytes() const { return offset_in_bytes_; }
+
+ private:
+  const intptr_t offset_in_bytes_;
+
+  DISALLOW_COPY_AND_ASSIGN(NativeStoreFieldComp);
+};
+
+
 class InstantiateTypeArgumentsComp : public TemplateComputation<1> {
  public:
   InstantiateTypeArgumentsComp(intptr_t token_index,