QA: minor code tweaks for memory usage

As discussed in PR 1356 in comment #1356 (comment) and originally discovered and addressed in squizlabs/PHP_CodeSniffer 2273

Author: jrfnl

src/Files/File.php

@@ -1899,8 +1899,9 @@ public function getMemberProperties(int $stackPtr)
 
         // Make sure it's not a method parameter.
         if (empty($this->tokens[$stackPtr]['nested_parenthesis']) === false) {
-            $parenthesis = array_keys($this->tokens[$stackPtr]['nested_parenthesis']);
-            $deepestOpen = array_pop($parenthesis);
+            $parentheses = $this->tokens[$stackPtr]['nested_parenthesis'];
+            $parentheses = array_keys($parentheses);
+            $deepestOpen = array_pop($parentheses);
             if ($deepestOpen > $ptr
                 && isset($this->tokens[$deepestOpen]['parenthesis_owner']) === true
                 && $this->tokens[$this->tokens[$deepestOpen]['parenthesis_owner']]['code'] === T_FUNCTION

src/Standards/Generic/Sniffs/WhiteSpace/ScopeIndentSniff.php

@@ -754,8 +754,9 @@ public function process(File $phpcsFile, int $stackPtr)
                 ) {
                     $isMethodPrefix = true;
                     if (isset($tokens[$checkToken]['nested_parenthesis']) === true) {
-                        $parenthesis = array_keys($tokens[$checkToken]['nested_parenthesis']);
-                        $deepestOpen = array_pop($parenthesis);
+                        $parentheses = $tokens[$checkToken]['nested_parenthesis'];
+                        $parentheses = array_keys($parentheses);
+                        $deepestOpen = array_pop($parentheses);
                         if (isset($tokens[$deepestOpen]['parenthesis_owner']) === true
                             && $tokens[$tokens[$deepestOpen]['parenthesis_owner']]['code'] === T_FUNCTION
                         ) {

src/Standards/Squiz/Sniffs/Formatting/OperatorBracketSniff.php

@@ -136,8 +136,9 @@ public function process(File $phpcsFile, int $stackPtr)
 
         $lastBracket = false;
         if (isset($tokens[$stackPtr]['nested_parenthesis']) === true) {
-            $parenthesis = array_reverse($tokens[$stackPtr]['nested_parenthesis'], true);
-            foreach ($parenthesis as $bracket => $endBracket) {
+            $parentheses = $tokens[$stackPtr]['nested_parenthesis'];
+            $parentheses = array_reverse($parentheses, true);
+            foreach ($parentheses as $bracket => $endBracket) {
                 $prevToken = $phpcsFile->findPrevious(T_WHITESPACE, ($bracket - 1), null, true);
                 $prevCode  = $tokens[$prevToken]['code'];
 

src/Standards/Squiz/Sniffs/WhiteSpace/OperatorSpacingSniff.php

@@ -350,8 +350,9 @@ protected function isOperator(File $phpcsFile, int $stackPtr)
         // Skip declare statements.
         if ($tokens[$stackPtr]['code'] === T_EQUAL) {
             if (isset($tokens[$stackPtr]['nested_parenthesis']) === true) {
-                $parenthesis = array_keys($tokens[$stackPtr]['nested_parenthesis']);
-                $bracket     = array_pop($parenthesis);
+                $parentheses = $tokens[$stackPtr]['nested_parenthesis'];
+                $parentheses = array_keys($parentheses);
+                $bracket     = array_pop($parentheses);
                 if (isset($tokens[$bracket]['parenthesis_owner']) === true) {
                     $function = $tokens[$bracket]['parenthesis_owner'];
                     if ($tokens[$function]['code'] === T_FUNCTION