X64 Crankshaft: Add DoOuterContext to x64 lithium.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
===================================================================
--- src/x64/lithium-x64.h	(revision 6911)
+++ src/x64/lithium-x64.h	(working copy)
@@ -129,6 +129,7 @@
   V(NumberUntagD)                               \
   V(ObjectLiteral)                              \
   V(OsrEntry)                                   \
+  V(OuterContext)                               \
   V(Parameter)                                  \
   V(PixelArrayLength)                           \
   V(Power)                                      \
@@ -1280,6 +1281,18 @@
 };
 
 
+class LOuterContext: public LTemplateInstruction<1, 1, 0> {
+ public:
+  explicit LOuterContext(LOperand* context) {
+    inputs_[0] = context;
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(OuterContext, "outer-context")
+
+  LOperand* context() { return InputAt(0); }
+};
+
+
 class LGlobalObject: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(GlobalObject, "global-object")