doc: update buffer.constants.MAX_LENGTH

Fixes: #38093

PR-URL: #38109
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Backport-PR-URL: #38232

doc/api/buffer.md

@@ -3140,12 +3140,20 @@ added: v8.2.0
 #### `buffer.constants.MAX_LENGTH`
 <!-- YAML
 added: v8.2.0
+changes:
+  - version: v14.0.0
+    pr-url: https://github.com/nodejs/node/pull/32116
+    description: Value is changed from 2<sup>31</sup> - 1 to
+      2<sup>32</sup> - 1 on 64-bit architectures.
 -->
 
 * {integer} The largest size allowed for a single `Buffer` instance.
 
 On 32-bit architectures, this value currently is 2<sup>30</sup> - 1 (~1GB).
-On 64-bit architectures, this value currently is 2<sup>31</sup> - 1 (~2GB).
+
+On 64-bit architectures, this value currently is 2<sup>32</sup> - 1 (~4GB).
+
+It reflects [`v8::TypedArray::kMaxLength`][] under the hood.
 
 This value is also available as [`buffer.kMaxLength`][].
 
@@ -3314,6 +3322,7 @@ introducing security vulnerabilities into an application.
 [`buffer.constants.MAX_STRING_LENGTH`]: #buffer_buffer_constants_max_string_length
 [`buffer.kMaxLength`]: #buffer_buffer_kmaxlength
 [`util.inspect()`]: util.md#util_util_inspect_object_options
+[`v8::TypedArray::kMaxLength`]: https://v8.github.io/api/head/classv8_1_1TypedArray.html#a54a48f4373da0850663c4393d843b9b0
 [binary strings]: https://developer.mozilla.org/en-US/docs/Web/API/DOMString/Binary
 [endianness]: https://en.wikipedia.org/wiki/Endianness
 [iterator]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols