Allow "loadHardpoints()" to accept a single ref and/or a single hardpoint

Summary: Ref T13490. There's more `array(...)` happening in this API than necessary. Sugar it slightly.

Test Plan: Grepped for "loadHardpoints()", ran a couple workflows.

Maniphest Tasks: T13490

Differential Revision: https://secure.phabricator.com/D21088

src/browse/workflow/ArcanistBrowseWorkflow.php

@@ -120,9 +120,7 @@ EOTEXT
 
     $this->loadHardpoints(
       $refs,
-      array(
+      ArcanistBrowseRef::HARDPOINT_URIS);
-        ArcanistBrowseRef::HARDPOINT_URIS,
-      ));
 
     $zero_hits = array();
     $open_uris = array();

src/workflow/ArcanistDiffWorkflow.php

@@ -3062,12 +3062,8 @@ EOTEXT
       ->setCommitRef($base_ref);
 
     $this->loadHardpoints(
-      array(
       $state_ref,
-      ),
+      ArcanistWorkingCopyStateRef::HARDPOINT_REVISIONREFS);
-      array(
-        ArcanistWorkingCopyStateRef::HARDPOINT_REVISIONREFS,
-      ));
 
     $revision_refs = $state_ref->getRevisionRefs();
     $viewer_phid = $this->getUserPHID();

src/workflow/ArcanistFeatureBaseWorkflow.php

@@ -79,10 +79,7 @@ EOHELP
 
     $this->loadHardpoints(
       ipull($states, 'state'),
-      array(
+      ArcanistWorkingCopyStateRef::HARDPOINT_REVISIONREFS);
-        ArcanistWorkingCopyStateRef::HARDPOINT_REVISIONREFS,
-      ));
-
 
     $this->printBranches($states);
 

src/workflow/ArcanistInspectWorkflow.php

@@ -98,9 +98,7 @@ EOTEXT
         if ($hardpoints) {
           $hardpoint_keys = mpull($hardpoints, 'getHardpointKey');
 
-          $this->loadHardpoints(
+          $this->loadHardpoints($refs, $hardpoint_keys);
-            $refs,
-            $hardpoint_keys);
         }
       }
     }

src/workflow/ArcanistWorkflow.php

@@ -2299,8 +2299,16 @@ abstract class ArcanistWorkflow extends Phobject {
   }
 
   final protected function loadHardpoints(
-    array $objects,
+    $objects,
-    array $requests) {
+    $requests) {
+
+    if (!is_array($objects)) {
+      $objects = array($objects);
+    }
+
+    if (!is_array($requests)) {
+      $requests = array($requests);
+    }
 
     $engine = $this->getHardpointEngine();