Support optimization of named function literals.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index e2f33b16dc1743571a57d1ea050ee88ddbbda70d..c0d989dc6c54885b43dc8d085602f803de5aa0eb 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -169,6 +169,7 @@ class LCodeGen;
   V(StringLength)                               \
   V(SubI)                                       \
   V(TaggedToI)                                  \
+  V(ThisFunction)                               \
   V(Throw)                                      \
   V(ToFastProperties)                           \
   V(Typeof)                                     \
@@ -1441,6 +1442,11 @@ class LPushArgument: public LTemplateInstruction<0, 1, 0> {
 };
 
 
+class LThisFunction: public LTemplateInstruction<1, 0, 0> {
+  DECLARE_CONCRETE_INSTRUCTION(ThisFunction, "this-function")
+};
+
+
 class LContext: public LTemplateInstruction<1, 0, 0> {
  public:
   DECLARE_CONCRETE_INSTRUCTION(Context, "context")