tameFunctionToString = () => {
  if (markVirtualizedNativeFunction === undefined) {
    const virtualizedNativeFunctions = new WeakSet();

    const tamingMethods = {
      toString() {
        const str = functionToString(this);
        if (
          stringEndsWith(str, nativeSuffix) ||
          !weaksetHas(virtualizedNativeFunctions, this)
        ) {
          return str;
        }
        return `function ${this.name}() { [native code] }`;
      },
    };

    defineProperty(functionPrototype, 'toString', {
      value: tamingMethods.toString,
    });

    markVirtualizedNativeFunction = freeze(func =>
      weaksetAdd(virtualizedNativeFunctions, func),
    );
  }
  return markVirtualizedNativeFunction;
}
Replace `Function.prototype.toString` with one that recognizes
shimmed functions as honorary native functions.