doc: add changelogs for v8

PR-URL: #11489
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Sam Roberts <[email protected]>
Reviewed-By: Roman Reiss <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Italo A. Casas <[email protected]>

Author: addaleax

doc/api/v8.md

@@ -12,6 +12,10 @@ const v8 = require('v8');
 ## v8.getHeapSpaceStatistics()
 <!-- YAML
 added: v6.0.0
+changes:
+  - version: v7.5.0
+    pr-url: https://github.com/nodejs/node/pull/10186
+    description: Support values exceeding the 32-bit unsigned integer range.
 -->
 
 Returns statistics about the V8 heap spaces, i.e. the segments which make up
@@ -72,6 +76,14 @@ For example:
 ## v8.getHeapStatistics()
 <!-- YAML
 added: v1.0.0
+changes:
+  - version: v7.2.0
+    pr-url: https://github.com/nodejs/node/pull/8610
+    description: Added `malloced_memory`, `peak_malloced_memory`,
+                 and `does_zap_garbage`.
+  - version: v7.5.0
+    pr-url: https://github.com/nodejs/node/pull/10186
+    description: Support values exceeding the 32-bit unsigned integer range.
 -->
 
 Returns an object with the following properties: