function _optionalChain(ops) {
  let lastAccessLHS = undefined;
  let value = ops[0];
  let i = 1;
  while (i < ops.length) {
    const op = ops[i] ;
    const fn = ops[i + 1] ;
    i += 2;
    // by checking for loose equality to `null`, we catch both `null` and `undefined`
    if ((op === 'optionalAccess' || op === 'optionalCall') && value == null) {
      // really we're meaning to return `undefined` as an actual value here, but it saves bytes not to write it
      return;
    }
    if (op === 'access' || op === 'optionalAccess') {
      lastAccessLHS = value;
      value = fn(value);
    } else if (op === 'call' || op === 'optionalCall') {
      value = fn((...args) => (value ).call(lastAccessLHS, ...args));
      lastAccessLHS = undefined;
    }
  }
  return value;
}
Polyfill for the optional chain operator, `?.`, given previous conversion of the expression into an array of values,
descriptors, and functions.

Adapted from Sucrase (https://github.com/alangpierce/sucrase)
See https://github.com/alangpierce/sucrase/blob/265887868966917f3b924ce38dfad01fbab1329f/src/transformers/OptionalChainingNullishTransformer.ts#L15

@param ops Array result of expression conversion
@returns The value of the expression