timers: use parseInt on timeout/repeat values

This results in a ~4-5% performance increase in the
'breadth' timers benchmark.

Author: mscdex

lib/timers.js

@@ -168,7 +168,7 @@ exports.active = function(item) {
 
 
 exports.setTimeout = function(callback, after) {
-  after *= 1; // coalesce to number or NaN
+  after = parseInt(after, 10); // coalesce to number or NaN
 
   if (!(after >= 1 && after <= TIMEOUT_MAX)) {
     after = 1; // schedule on next tick, follows browser behaviour
@@ -224,7 +224,7 @@ exports.clearTimeout = function(timer) {
 
 
 exports.setInterval = function(callback, repeat) {
-  repeat *= 1; // coalesce to number or NaN
+  repeat = parseInt(repeat, 10); // coalesce to number or NaN
 
   if (!(repeat >= 1 && repeat <= TIMEOUT_MAX)) {
     repeat = 1; // schedule on next tick, follows browser behaviour