Add Composer autoloading functions and PHPStan for testing

vendor/nikic/php-parser/test/code/parser/stmt/hashbang.test

@@ -0,0 +1,26 @@
+Hashbang line
+-----
+#!/usr/bin/env php
+<?php
+
+echo "foobar";
+
+?>
+#!/usr/bin/env php
+-----
+array(
+    0: Stmt_InlineHTML(
+        value: #!/usr/bin/env php
+
+    )
+    1: Stmt_Echo(
+        exprs: array(
+            0: Scalar_String(
+                value: foobar
+            )
+        )
+    )
+    2: Stmt_InlineHTML(
+        value: #!/usr/bin/env php
+    )
+)