Revert of Add script context with context-allocated "const this"

src/variables.h

Index: src/variables.h
diff --git a/src/variables.h b/src/variables.h
index 218eefae08e08a0cd937a14e1d158c5b878d1a0c..0cb50c87e985580c1fd1c7fc5ea9b3fde63f4206 100644
--- a/src/variables.h
+++ b/src/variables.h
@@ -104,16 +104,6 @@
   bool is_class() const { return kind_ == CLASS; }
   bool is_this() const { return kind_ == THIS; }
   bool is_arguments() const { return kind_ == ARGUMENTS; }
-
-  // For script scopes, the "this" binding is provided by a ScriptContext added
-  // to the global's ScriptContextTable.  This binding might not statically
-  // resolve to a Variable::THIS binding, instead being DYNAMIC_LOCAL.  However
-  // any variable named "this" does indeed refer to a Variable::THIS binding;
-  // the grammar ensures this to be the case.  So wherever a "this" binding
-  // might be provided by the global, use HasThisName instead of is_this().
-  bool HasThisName(Isolate* isolate) const {
-    return is_this() || *name() == *isolate->factory()->this_string();
-  }
 
   ClassVariable* AsClassVariable() {
     DCHECK(is_class());