Use instanceof instead of getclass

Signed-off-by: Michal Čihař <michal@cihar.com>

Author: nijel

src/Statement.php

@@ -255,7 +255,7 @@ public function parse(Parser $parser, TokensList $list)
             // ON DUPLICATE KEY UPDATE ...
             // has to be parsed in parent statement (INSERT or REPLACE)
             // so look for it and break
-            if (get_class($this) === 'PhpMyAdmin\SqlParser\Statements\SelectStatement'
+            if ($this instanceof \PhpMyAdmin\SqlParser\Statements\SelectStatement
                 && $token->value === 'ON'
             ) {
                 ++$list->idx; // Skip ON
@@ -351,7 +351,7 @@ public function parse(Parser $parser, TokensList $list)
             } elseif ($class === null) {
                 // Handle special end options in Select statement
                 // See Statements\SelectStatement::$END_OPTIONS
-                if (get_class($this) === 'PhpMyAdmin\SqlParser\Statements\SelectStatement'
+                if ($this instanceof \PhpMyAdmin\SqlParser\Statements\SelectStatement
                     && ($token->value === 'FOR UPDATE'
                     || $token->value === 'LOCK IN SHARE MODE')
                 ) {