Restore "arc alias" shell aliases

Summary:
See <https://discourse.phabricator-community.org/t/exception-when-trying-to-run-an-arc-alias-undefined-method-arcanistalias-getshellcommand/3731/>.

Shell aliases got lost in the shuffle of porting "arc alias"; restore them.

Test Plan: Bound `arc ls` to `ls -alh`, ran `arc ls`.

Differential Revision: https://secure.phabricator.com/D21084

src/runtime/ArcanistRuntime.php

@@ -141,6 +141,12 @@ final class ArcanistRuntime {
       ->setConfigurationSourceList($config)
       ->resolveAliases($unconsumed_argv);
 
+    foreach ($alias_effects as $alias_effect) {
+      if ($alias_effect->getType() === ArcanistAliasEffect::EFFECT_SHELL) {
+        return $this->executeShellAlias($alias_effect);
+      }
+    }
+
     $result_argv = $this->applyAliasEffects($alias_effects, $unconsumed_argv);
 
     $args->setUnconsumedArgumentVector($result_argv);
@@ -727,4 +733,15 @@ final class ArcanistRuntime {
     return $engine;
   }
 
+  private function executeShellAlias(ArcanistAliasEffect $effect) {
+    $log = $this->getLogEngine();
+
+    $message = $effect->getMessage();
+    if ($message !== null) {
+      $log->writeHint(pht('SHELL ALIAS'), $message);
+    }
+
+    return phutil_passthru('%Ls', $effect->getArguments());
+  }
+
 }

src/toolset/ArcanistAliasEngine.php

@@ -199,22 +199,31 @@ final class ArcanistAliasEngine
       }
     }
 
+    $alias_argv = $alias->getCommand();
+    $alias_command = array_shift($alias_argv);
+
     if ($alias->isShellCommandAlias()) {
+      $shell_command = substr($alias_command, 1);
+
+      $shell_argv = array_merge(
+        array($shell_command),
+        $alias_argv,
+        $argv);
+
+      $shell_display = csprintf('%Ls', $shell_argv);
+
       $results[] = $this->newEffect(ArcanistAliasEffect::EFFECT_SHELL)
         ->setMessage(
           pht(
             '%s %s -> $ %s',
             $toolset_key,
             $command,
-            $alias->getShellCommand()))
-        ->setCommand($command)
-        ->setArgv($argv);
+            $shell_display))
+        ->setArguments($shell_argv);
+
       return $results;
     }
 
-    $alias_argv = $alias->getCommand();
-    $alias_command = array_shift($alias_argv);
-
     if (isset($stack[$alias_command])) {
 
       $cycle = array_keys($stack);