Redirect most NewUnresolved calls over Parser

src/parsing/parser.h

Index: src/parsing/parser.h
diff --git a/src/parsing/parser.h b/src/parsing/parser.h
index 8f7bf0884ba5a91fbbb8d749201fe3c6c49db3ce..97b579b024126717df6919fbab2f9f9612d5a0e9 100644
--- a/src/parsing/parser.h
+++ b/src/parsing/parser.h
@@ -549,17 +549,15 @@ class ParserTraits {
   const AstRawString* GetNextSymbol(Scanner* scanner);
   const AstRawString* GetNumberAsSymbol(Scanner* scanner);
 
-  Expression* ThisExpression(AstNodeFactory* factory,
-                             int pos = kNoSourcePosition);
+  Expression* ThisExpression(int pos);
   Expression* NewSuperPropertyReference(AstNodeFactory* factory, int pos);
   Expression* NewSuperCallReference(AstNodeFactory* factory, int pos);
-  Expression* NewTargetExpression(AstNodeFactory* factory, int pos);
+  Expression* NewTargetExpression(int pos);
   Expression* FunctionSentExpression(AstNodeFactory* factory, int pos);
   Literal* ExpressionFromLiteral(Token::Value token, int pos, Scanner* scanner,
                                  AstNodeFactory* factory);
   Expression* ExpressionFromIdentifier(const AstRawString* name,
-                                       int start_position, int end_position,
-                                       AstNodeFactory* factory);
+                                       int start_position, int end_position);
   Expression* ExpressionFromString(int pos, Scanner* scanner,
                                    AstNodeFactory* factory);
   Expression* GetIterator(Expression* iterable, AstNodeFactory* factory,
@@ -1086,6 +1084,9 @@ class Parser : public ParserBase<ParserTraits> {
                                             bool* ok);
 
   static InitializationFlag DefaultInitializationFlag(VariableMode mode);
+  VariableProxy* NewUnresolved(const AstRawString* name, Variable::Kind kind,
+                               int begin_pos, int end_pos = kNoSourcePosition,
+                               VariableMode mode = LET);

[adamk, 2016/08/09 20:11:45]

The "mode" argument on NewUnresolved makes very little sense. I wonder what
would happen if we just removed it and always added the unresolved VariableProxy
to the current scope.

   VariableProxy* NewUnresolved(const AstRawString* name, VariableMode mode);
   Variable* Declare(Declaration* declaration,
                     DeclarationDescriptor::Kind declaration_kind,