Summary:
This would fix test errors caused by including <string> in non-C++ compatible files.
Changelog:
[General][Changed] - Remove usage of std::string in EarlyJsErrorHandler.
Reviewed By: RSNara
Differential Revision: D35645334
fbshipit-source-id: 7f04d2c66d53dc1eef63367de1a64ed9273898f5