Reapply r9870 "Remove some initialization checks based on source positions.".

src/variables.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 48 matching lines @@
                    VariableMode mode,
                    bool is_valid_LHS,
                    Kind kind,
                    InitializationFlag initialization_flag)
   : scope_(scope),
     name_(name),
     mode_(mode),
     kind_(kind),
     location_(UNALLOCATED),
     index_(-1),
+    initializer_position_(RelocInfo::kNoPosition),
     local_if_not_shadowed_(NULL),
     is_valid_LHS_(is_valid_LHS),
     force_context_allocation_(false),
     is_used_(false),
     initialization_flag_(initialization_flag) {
   // Names must be canonicalized for fast equality checks.
   ASSERT(name->IsSymbol());
   // Var declared variables never need initialization.
   ASSERT(!(mode == VAR && initialization_flag == kNeedsInitialization));
 }
 
 
 bool Variable::is_global() const {
   // Temporaries are never global, they must always be allocated in the
   // activation frame.
   return mode_ != TEMPORARY && scope_ != NULL && scope_->is_global_scope();
 }
 
 
 int Variable::CompareIndex(Variable* const* v, Variable* const* w) {
   int x = (*v)->index();
   int y = (*w)->index();
   // Consider sorting them according to type as well?
   return x - y;
 }
 
 } }  // namespace v8::internal