Crash when calling JSON.stringify on an AbstractValue

[sb98052]

(function () {
  let o = __abstract("object", "(o)");
  let s;
  s = "A" + JSON.stringify(o);

  global.s = s;
})();

leads to:

Invariant Violation:                                                                                   
This is likely a bug in Prepack, not your code. Feel free to open an issue on GitHub.          
    at invariant (/Users/gwsapan/Projects/prepack/lib/invariant.js:24:15)                               
    at ValuesDomain.getElements (/Users/gwsapan/Projects/prepack/lib/domains/ValuesDomain.js:71:28)          
    at AbstractObjectValue.getTemplate (/Users/gwsapan/Projects/prepack/lib/values/AbstractObjectValue.js:42:37)
    at InternalJSONClone (/Users/gwsapan/Projects/prepack/lib/intrinsics/ecma262/JSON.js:302:87)
    at NativeFunctionValue.obj.defineNativeMethod [as callback] (/Users/gwsapan/Projects/prepack/lib/intrinsics/ecma262
/JSON.js:471:25)
    at NativeFunctionValue.callCallback (/Users/gwsapan/Projects/prepack/lib/values/NativeFunctionValue.js:85:51)
    at functionCall (/Users/gwsapan/Projects/prepack/lib/methods/call.js:248:26)
    at callNativeFunctionValue (/Users/gwsapan/Projects/prepack/lib/methods/call.js:274:10)
    at OrdinaryCallEvaluateBody (/Users/gwsapan/Projects/prepack/lib/methods/call.js:280:12)
    at InternalCall (/Users/gwsapan/Projects/prepack/lib/methods/function.js:80:49)
    at FunctionImplementation.$Call (/Users/gwsapan/Projects/prepack/lib/methods/function.js:748:12)
    at NativeFunctionValue.$Call (/Users/gwsapan/Projects/prepack/lib/values/NativeFunctionValue.js:25:36)
    at Call (/Users/gwsapan/Projects/prepack/lib/methods/call.js:494:12)