doc,test: update v8 method doc and comment

Update documentation and test comment for v8.cachedDataVersionTag().

PR-URL: #35795
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>

Author: Trott

doc/api/v8.md

@@ -18,11 +18,20 @@ added: v8.0.0
 
 * Returns: {integer}
 
-Returns an integer representing a "version tag" derived from the V8 version,
-command-line flags and detected CPU features. This is useful for determining
+Returns an integer representing a version tag derived from the V8 version,
+command-line flags, and detected CPU features. This is useful for determining
 whether a [`vm.Script`][] `cachedData` buffer is compatible with this instance
 of V8.
 
+```js
+console.log(v8.cachedDataVersionTag()); // 3947234607
+// The value returned by v8.cachedDataVersionTag() is derived from the V8
+// version, command-line flags, and detected CPU features. Test that the value
+// does indeed update when flags are toggled.
+v8.setFlagsFromString('--allow_natives_syntax');
+console.log(v8.cachedDataVersionTag()); // 183726201
+```
+
 ## `v8.getHeapSpaceStatistics()`
 <!-- YAML
 added: v6.0.0

test/parallel/test-v8-version-tag.js

@@ -7,9 +7,9 @@ const versionTag1 = v8.cachedDataVersionTag();
 assert.strictEqual(typeof versionTag1, 'number');
 assert.strictEqual(v8.cachedDataVersionTag(), versionTag1);
 
-// The value of cachedDataVersionTag is derived from the command line flags and
-// detected CPU features. Test that the value does indeed update when flags
-// are toggled.
+// The value returned by v8.cachedDataVersionTag() is derived from the V8
+// version, command-line flags, and detected CPU features. Test that the value
+// does indeed update when flags are toggled.
 v8.setFlagsFromString('--allow_natives_syntax');
 
 const versionTag2 = v8.cachedDataVersionTag();