1. initialize message variable of ErrorObject correctly

2. merge DeclareFunctionDeclaration, DeclareFunctionDeclarationsInGlobal into DeclareFunctionDeclarations
3. implement EnvironmentRecord::initializeBinding for initialize function decl.

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

src/parser/Script.cpp

@@ -85,7 +85,7 @@ Script::ScriptSandboxExecuteResult Script::sandboxExecute(Context* ctx)
     ExecutionState stateForInit(ctx);
 
     auto sandBoxResult = sb.run([&]() -> Value {
-        return execute(stateForInit);
+        return execute(stateForInit, false, false, true);
     });
     result.result = sandBoxResult.result;
     result.msgStr = sandBoxResult.msgStr;