http: include provided status code in range error

ServerResponse#writeHead() coerces the user provided status code
to a number and then performs a range check. If the check fails,
a range error is thrown. The coerced status code is included in
the error message. This commit uses the user provided status code
instead.

PR-URL: https://github.com/nodejs/node/pull/11221
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/_http_server.js

@@ -161,9 +161,11 @@ ServerResponse.prototype._implicitHeader = function _implicitHeader() {
 
 ServerResponse.prototype.writeHead = writeHead;
 function writeHead(statusCode, reason, obj) {
+  var originalStatusCode = statusCode;
+
   statusCode |= 0;
   if (statusCode < 100 || statusCode > 999)
-    throw new RangeError(`Invalid status code: ${statusCode}`);
+    throw new RangeError(`Invalid status code: ${originalStatusCode}`);
 
   if (typeof reason === 'string') {
     // writeHead(statusCode, reasonPhrase[, headers])