test: allow for slow hosts in spawnSync() test

test-child-process-spawnsync-timeout failed from time to time on
Raspberry Pi devices. Use common.platformTimeout() to allow a little
more time to run on resource-constrained hosts.

PR-URL: https://github.com/nodejs/node/pull/10998
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

test/parallel/test-child-process-spawnsync-timeout.js

@@ -1,11 +1,11 @@
 'use strict';
-require('../common');
-var assert = require('assert');
+const common = require('../common');
+const assert = require('assert');
 
 var spawnSync = require('child_process').spawnSync;
 
-var TIMER = 200;
-var SLEEP = 5000;
+const TIMER = 200;
+const SLEEP = common.platformTimeout(5000);
 
 switch (process.argv[2]) {
   case 'child':
@@ -19,8 +19,7 @@ switch (process.argv[2]) {
     var ret = spawnSync(process.execPath, [__filename, 'child'],
                         {timeout: TIMER});
     assert.strictEqual(ret.error.errno, 'ETIMEDOUT');
-    console.log(ret);
-    var end = Date.now() - start;
+    const end = Date.now() - start;
     assert(end < SLEEP);
     assert(ret.status > 128 || ret.signal);
     break;