[test] Add core `test-http-head-request` test

Modifications:

  * make client connect to `PROXY_PORT` instead of `PORT`

test/core/simple/test-http-head-request.js

+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+var http = require('http');
+var util = require('util');
+
+
+var body = 'hello world\n';
+
+var server = http.createServer(function(req, res) {
+  common.error('req: ' + req.method);
+  res.writeHead(200, {'Content-Length': body.length});
+  res.end();
+  server.close();
+});
+
+var gotEnd = false;
+
+server.listen(common.PORT, function() {
+  var request = http.request({
+    port: common.PROXY_PORT,
+    method: 'HEAD',
+    path: '/'
+  }, function(response) {
+    common.error('response start');
+    response.on('end', function() {
+      common.error('response end');
+      gotEnd = true;
+    });
+  });
+  request.end();
+});
+
+process.on('exit', function() {
+  assert.ok(gotEnd);
+});