Symbols cannot be defined as a property

[jasonwilliams]

var obj = {};
var s = Symbol('1');
Object.defineProperty(obj, s);

Outputs: Uncaught "TypeError": "can't convert symbol to string"

The problem starts here:
https://github.com/boa-dev/boa/blob/master/boa/src/builtins/object/mod.rs#L101 we try to coarce the key into a string type. We shouldn't need to do this as Property's already support Symbols as keys. We should pass the argument straight through to PropertyKey::from() and let it sort it out.

PropertyKey is defined here:
https://github.com/boa-dev/boa/blob/master/boa/src/property/mod.rs#L290-L294

Contributing: https://github.com/boa-dev/boa/blob/master/CONTRIBUTING.md
Debugging: https://github.com/boa-dev/boa/blob/master/docs/debugging.md

[georgeroman]

I can take this one.

[jasonwilliams]

Thanks @georgeroman assigned