[Error builtin] does not output "name" property correctly

[croraf]

Describe the bug
Error builtin and its subclasses don't output "name" property correctly

To Reproduce
new Error().name;
should show "Error", instead it shows Uncaught "Error": ""

also new SyntaxError().name;
should show "SyntaxError", instead it shows Uncaught "SyntaxError": ""

Environment

• OS: [e.g. Fedora Linux]
• Version: [e.g. 32]
• Target triple: [e.g. x86_64-unknown-linux-gnu]
• Rustc version: [e.g. rustc 1.43.0 (4fb7144ed 2020-04-20), running rustc -V]

Additional context

[HalidOdat]

@croraf I think #749 should fix this issue, right? since new Error() or Error() just throws the error immediately

[croraf]

I don't know if it will fix it, but if "new Error()" throws immediately, we should definitely prioritize that PR, and then check this again.

[RageKnify]

Yeah, #749 will fix this.