1. do not ASTScopeContext explicitly. it is used by ByteCode-genaration

2. alloc esprima::Error as Non-GC type.
 - it can be thrown. but, bdwgc can not see try-catch variable area.
3. Use own context when eval, function are invoked.
4. implement fake-Realm class for v8 vender test

Signed-off-by: seonghyun kim <sh8281.kim@samsung.com>

src/parser/esprima_cpp/esprima.cpp

@@ -484,7 +484,7 @@ public:
 
     Error* constructError(String* msg, size_t column)
     {
-        Error* error = new Error(msg);
+        Error* error = new (NoGC) Error(msg);
         error->column = column;
         return error;
         // try {