process: use validateString validator

Use the `validateString()` validator where applicable.

PR-URL: #41595
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

lib/internal/process/report.js

@@ -1,6 +1,5 @@
 'use strict';
 const {
-  ERR_INVALID_ARG_TYPE,
   ERR_SYNTHETIC
 } = require('internal/errors').codes;
 const {
@@ -18,9 +17,11 @@ const report = {
     if (typeof file === 'object' && file !== null) {
       err = file;
       file = undefined;
-    } else if (file !== undefined && typeof file !== 'string') {
-      throw new ERR_INVALID_ARG_TYPE('file', 'String', file);
-    } else if (err === undefined) {
+    } else if (file !== undefined) {
+      validateString(file, 'file');
+    }
+
+    if (err === undefined) {
       err = new ERR_SYNTHETIC();
     } else {
       validateObject(err, 'err');