Squiz/ClosingDeclarationComment: add trait support

Now this sniff will also check for the closing declaration comment in
traits.

Author: rodrigoprimo

src/Standards/Squiz/Sniffs/Commenting/ClosingDeclarationCommentSniff.php

@@ -1,6 +1,6 @@
 <?php
 /**
- * Checks the //end ... comments on classes, interfaces and functions.
+ * Checks the //end ... comments on classes, enums, functions, interfaces and traits.
  *
  * @author    Greg Sherwood <[email protected]>
  * @copyright 2006-2015 Squiz Pty Ltd (ABN 77 084 670 600)
@@ -28,6 +28,7 @@ public function register()
             T_ENUM,
             T_FUNCTION,
             T_INTERFACE,
+            T_TRAIT,
         ];
 
     }//end register()
@@ -72,6 +73,8 @@ public function process(File $phpcsFile, $stackPtr)
             $comment = '//end class';
         } else if ($tokens[$stackPtr]['code'] === T_INTERFACE) {
             $comment = '//end interface';
+        } else if ($tokens[$stackPtr]['code'] === T_TRAIT) {
+            $comment = '//end trait';
         } else {
             $comment = '//end enum';
         }//end if

src/Standards/Squiz/Tests/Commenting/ClosingDeclarationCommentUnitTest.1.inc

@@ -116,3 +116,9 @@ $anon = new class {};
 
 // Arrow functions don't need end comments.
 $arrow = fn($a) => $a;
+
+trait TestTrait {
+}//end trait
+
+trait TestTrait {
+}

src/Standards/Squiz/Tests/Commenting/ClosingDeclarationCommentUnitTest.1.inc.fixed

@@ -109,3 +109,9 @@ $anon = new class {};
 
 // Arrow functions don't need end comments.
 $arrow = fn($a) => $a;
+
+trait TestTrait {
+}//end trait
+
+trait TestTrait {
+}//end trait

src/Standards/Squiz/Tests/Commenting/ClosingDeclarationCommentUnitTest.php

@@ -50,6 +50,7 @@ public function getErrorList($testFile='')
                 101 => 1,
                 106 => 1,
                 110 => 1,
+                124 => 1,
             ];
 
         case 'ClosingDeclarationCommentUnitTest.4.inc':