Debug protocol is not 100% JSON compliant

Don't know whether this is known or not but I figured I'd bring it up in case this was a bug or oversight: I've found that when inspecting values using the debugger API (for example, a result of JsDiagEvaluate), for at least `NaN` and +/- `Infinity`, these values are provided directly as the "value" property of the serialized object. NaN and Infinity are not encodable in JSON and will be coerced to `null` (losing information) if the object is actually converted to JSON.