Fix "AphrontRequest->getRequestURI()" for requests with "x[]=1" parameters in the URI

Summary:
Ref T13250. See PHI1069. This is a small fix for `getRequestURI()` currently not working if the request includes "x[]=..." PHP-flavored array parameters, beacause they're parsed into arrays by `$_GET` and `setQueryParams(...)` no longer accepts nonscalars.

Instead, just parse the raw request URI.

Test Plan: Visited `/search/hovercard/?phids[]=X`, no more fatal. Dumped the resulting URI, saw it had the right value. Tried `?phids[]=x&x=1&x=1&x=1`, saw the parameters correctly preserved.

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T13250

Differential Revision: https://secure.phabricator.com/D20147

Author: epriestley

src/aphront/AphrontRequest.php

@@ -591,10 +591,15 @@ public function getViewer() {
   }
 
   public function getRequestURI() {
-    $get = $_GET;
-    unset($get['__path__']);
+    $request_uri = idx($_SERVER, 'REQUEST_URI', '/');
+
+    $uri = new PhutilURI($request_uri);
+    $uri->setQueryParam('__path__', null);
+
     $path = phutil_escape_uri($this->getPath());
-    return id(new PhutilURI($path))->setQueryParams($get);
+    $uri->setPath($path);
+
+    return $uri;
   }
 
   public function getAbsoluteRequestURI() {