Parse harmony let declarations.

src/preparser.h

Index: src/preparser.h
diff --git a/src/preparser.h b/src/preparser.h
index 3d72c97e2691862349b16416591314641ee4695a..cd0a530e8d0bba8b368510601e30ff566a00cb49 100644
--- a/src/preparser.h
+++ b/src/preparser.h
@@ -77,6 +77,12 @@ class PreParser {
     kFunctionScope
   };
 
+  enum VariableDeclarationContext {
+    kSourceElement,
+    kStatement,
+    kForStatement
+  };
+
   class Expression;
 
   class Identifier {
@@ -344,7 +350,8 @@ class PreParser {
         strict_mode_violation_type_(NULL),
         stack_overflow_(false),
         allow_lazy_(true),
-        parenthesized_function_(false) { }
+        parenthesized_function_(false),
+        harmony_block_scoping_(scanner->HarmonyBlockScoping()) { }
 
   // Preparse the program. Only called in PreParseProgram after creating
   // the instance.
@@ -377,12 +384,16 @@ class PreParser {
   // which is set to false if parsing failed; it is unchanged otherwise.
   // By making the 'exception handling' explicit, we are forced to check
   // for failure at the call sites.
+  Statement ParseSourceElement(bool* ok);
   SourceElements ParseSourceElements(int end_token, bool* ok);
   Statement ParseStatement(bool* ok);
   Statement ParseFunctionDeclaration(bool* ok);
   Statement ParseBlock(bool* ok);
-  Statement ParseVariableStatement(bool* ok);
-  Statement ParseVariableDeclarations(bool accept_IN, int* num_decl, bool* ok);
+  Statement ParseVariableStatement(VariableDeclarationContext var_context,
+                                   bool* ok);
+  Statement ParseVariableDeclarations(VariableDeclarationContext var_context,
+                                      int* num_decl,
+                                      bool* ok);
   Statement ParseExpressionOrLabelledStatement(bool* ok);
   Statement ParseIfStatement(bool* ok);
   Statement ParseContinueStatement(bool* ok);
@@ -496,6 +507,7 @@ class PreParser {
   bool stack_overflow_;
   bool allow_lazy_;
   bool parenthesized_function_;
+  bool harmony_block_scoping_;
 };
 } }  // v8::preparser