assert() does not give pretty error messages

[jackhorton]

f76ef504326f8a37cdb0d3dae705239d685abffc brought in a significant change to assert.js that uses V8 internal APIs to read the stack to find the assert callsite in order to use the program source code as the default message if one was not provided to assert(). c5a23c47f30406c1fb204e5c1d9047b23fb2d54c disables this functionality for node-chakracore, but it would be nice to add it back eventually.