profiler: declare missing `printErr`

`v8/tools/tickprocessor.js` assumes presence of global `printErr`, which
is defined in `d8`.

PR-URL: https://github.com/nodejs/node/pull/13590
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

lib/internal/v8_prof_processor.js

@@ -18,6 +18,11 @@ scriptFiles.forEach(function(s) {
   script += process.binding('natives')[s] + '\n';
 });
 
+// eslint-disable-next-line no-unused-vars
+function printErr(err) {
+  console.error(err);
+}
+
 const tickArguments = [];
 if (process.platform === 'darwin') {
   tickArguments.push('--mac');