Squiz/DisallowComparisonAssignment: fix sniff to work with the PHP 8 identifier tokens

Includes extra unit tests covering the change in so far it wasn't already covered.

Note: this was previously a false positive for this sniff!

Author: jrfnl

src/Standards/Squiz/Sniffs/PHP/DisallowComparisonAssignmentSniff.php

@@ -68,18 +68,16 @@ public function process(File $phpcsFile, $stackPtr)
         }
 
         // Ignore function calls.
-        $ignore = [
-            T_NULLSAFE_OBJECT_OPERATOR,
-            T_OBJECT_OPERATOR,
-            T_STRING,
-            T_VARIABLE,
-            T_WHITESPACE,
-        ];
+        $ignore   = Tokens::$nameTokens;
+        $ignore[] = T_NULLSAFE_OBJECT_OPERATOR;
+        $ignore[] = T_OBJECT_OPERATOR;
+        $ignore[] = T_VARIABLE;
+        $ignore[] = T_WHITESPACE;
 
         $next = $phpcsFile->findNext($ignore, ($stackPtr + 1), null, true);
         if ($tokens[$next]['code'] === T_CLOSURE
             || ($tokens[$next]['code'] === T_OPEN_PARENTHESIS
-            && $tokens[($next - 1)]['code'] === T_STRING)
+            && isset(Tokens::$nameTokens[$tokens[($next - 1)]['code']]) === true)
         ) {
             // Code will look like: $var = myFunction(
             // and will be ignored.

src/Standards/Squiz/Tests/PHP/DisallowComparisonAssignmentUnitTest.inc

@@ -81,3 +81,7 @@ function issue3616() {
         $food === 'cake' => 'This food is a cake',
     };
 }
+
+$var = \Fully\qualified(!$var);
+$var = Partially\qualified(!$var);
+$var = namespace\relative(!$var);