doc: document fs.watchFile() bigint option

This commit documents the bigint option to fs.watchFile(), which has been supported since v10.5.0. PR-URL: #32128 Reviewed-By: Luigi Pinca <[email protected]> Reviewed-By: Anna Henningsen <[email protected]> Reviewed-By: Richard Lau <[email protected]>

Author: cjihrig

doc/api/fs.md

@@ -3820,6 +3820,9 @@ fs.watch('somedir', (eventType, filename) =>{
 <!-- YAML
 added: v0.1.31
 changes:
+ - version: v10.5.0
+ pr-url: https://github.com/nodejs/node/pull/20220
+ description: The `bigint` option is now supported.
  - version: v7.6.0
  pr-url: https://github.com/nodejs/node/pull/10739
  description: The `filename` parameter can be a WHATWG `URL` object using
@@ -3828,6 +3831,7 @@ changes:
 
 *`filename`{string|Buffer|URL}
 *`options`{Object}
+*`bigint`{boolean} **Default:**`false`
 *`persistent`{boolean} **Default:**`true`
 *`interval`{integer} **Default:**`5007`
 *`listener`{Function}
@@ -3853,7 +3857,8 @@ fs.watchFile('message.text', (curr, prev) =>{
 });
 ```
 
-These stat objects are instances of `fs.Stat`.
+These stat objects are instances of `fs.Stat`. If the `bigint` option is `true`,
+the numeric values in these objects are specified as `BigInt`s.
 
 To be notified when the file was modified, not just accessed, it is necessary
 to compare `curr.mtime` and `prev.mtime`.