Update gnsr.php

Author: staabm

tests/PHPStan/Analyser/Generator/data/gnsr.php

@@ -247,11 +247,16 @@ function doCast() {
 		assertType("'1'", (string) $a);
 	}
 
-	function doInterpolatedString() {
+	/**
+	 * @param '1' $b
+	 */
+	function doInterpolatedString(string $b) {
 		$a = '1';
 
 		assertType("'1'", "$a");
 		assertNativeType("'1'", "$a");
+		assertType("'1'", "$b");
+		assertNativeType("string", "$b");
 	}