TypeCastSniff: Fixed internal error

Author: kukulich

SlevomatCodingStandard/Sniffs/PHP/TypeCastSniff.php

@@ -58,6 +58,10 @@ public function process(File $phpcsFile, $pointer): void
 
 		preg_match('~^\(\s*(\S+)\s*\)\z~i', $cast, $matches);
 
+		if (!array_key_exists(1, $matches)) {
+			return;
+		}
+
 		$castName = $matches[1];
 		$castNameLower = strtolower($castName);
 

tests/Sniffs/PHP/data/typeCastNoErrors.php

@@ -13,3 +13,5 @@
 (string ) 123;
 ( string ) 123;
 
+b"\xEF\xBB\xBF";
+