Remove some unnecessary binding initialization checks.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 021ad4cc76fcad76c3e847d6804120fdd3c5068f..df7d95d722b0ceb39574f420c11aa460aa8a1053 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3173,18 +3173,25 @@ class ScopeInfo : public FixedArray {
   // Return the mode of the given context local.
   VariableMode context_local_mode(int var);
 
+  // Return the initialization flag of the given context local.
+  InitializationFlag context_local_init_flag(int var);
+
   // Lookup support for serialized scope info. Returns the
   // the stack slot index for a given slot name if the slot is
   // present; otherwise returns a value < 0. The name must be a symbol
   // (canonicalized).
   int StackSlotIndex(String* name);
 
-  // Lookup support for serialized scope info. Returns the
-  // context slot index for a given slot name if the slot is present; otherwise
-  // returns a value < 0. The name must be a symbol (canonicalized).
-  // If the slot is present and mode != NULL, sets *mode to the corresponding
-  // mode for that variable.
-  int ContextSlotIndex(String* name, VariableMode* mode = NULL);
+  // Lookup support for serialized scope info. Returns the context slot index
+  // for a given slot name if the slot is present; otherwise returns a
+  // value < 0. The name must be a symbol (canonicalized).
+  // If the slot is present
+  //  1. and mode != NULL, sets *mode to the mode of that variable.
+  //  2. and init_flag != NULL, sets *init_flag to the initialization flag of
+  //     that variable.
+  int ContextSlotIndex(String* name,
+                       VariableMode* mode = NULL,
+                       InitializationFlag* init_flag = NULL);
 
   // Lookup support for serialized scope info. Returns the
   // parameter index for a given parameter name if the parameter is present;
@@ -3257,10 +3264,11 @@ class ScopeInfo : public FixedArray {
   //    index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per
   //    context local, so in total this part occupies num_context_locals()
   //    slots in the array.
-  // 4. ContextLocalModeEntries:
-  //    Contains the variable modes corresponding to the context locals in
-  //    ContextLocalNameEntries. One slot is used per context local, so in total
-  //    this part occupies num_context_locals() slots in the array.
+  // 4. ContextLocalInfoEntries:
+  //    Contains the variable modes and initialization flags corresponding to
+  //    the context locals in ContextLocalNameEntries. One slot is used per
+  //    context local, so in total this part occupies num_context_locals()
+  //    slots in the array.
   // 5. FunctionNameEntryIndex:
   //    If the scope belongs to a named function expression this part contains
   //    information about the function variable. It always occupies two array
@@ -3269,7 +3277,7 @@ class ScopeInfo : public FixedArray {
   int ParameterEntriesIndex();
   int StackLocalEntriesIndex();
   int ContextLocalNameEntriesIndex();
-  int ContextLocalModeEntriesIndex();
+  int ContextLocalInfoEntriesIndex();
   int FunctionNameEntryIndex();
 
   // Location of the function variable for named function expressions.
@@ -3286,6 +3294,11 @@ class ScopeInfo : public FixedArray {
   class StrictModeField:       public BitField<bool,                 4, 1> {};
   class FunctionVariableField: public BitField<FunctionVariableInfo, 5, 2> {};
   class FunctionVariableMode:  public BitField<VariableMode,         7, 3> {};
+
+  // BitFields representing the encoded information for context locals in the
+  // ContextLocalInfoEntries part.
+  class ContextLocalMode:      public BitField<VariableMode,         0, 3> {};
+  class ContextLocalInitFlag:  public BitField<InitializationFlag,   3, 1> {};
 };