Add test for GH-15903

Author: dstogov

ext/opcache/tests/jit/gh15903.phpt

@@ -0,0 +1,20 @@
+--TEST--
+GH-15903 (Core dumped in ext/opcache/jit/ir/ir_ra.c)
+--EXTENSIONS--
+opcache
+--INI--
+opcache.jit=1002
+opcache.jit_buffer_size=64M
+--FILE--
+<?php
+for ($i = 0; $i < 2; ++$i) { //This must run >=2 (increasing the number of elements in the array *2 will not do)
+foreach (array_fill(0, 389, 'x') as &$params) { //Will not trigger <389
+$x[] = new foo;
+}
+}
+?>
+--EXPECTF--
+Fatal error: Uncaught Error: Class "foo" not found in %sgh15903.php:4
+Stack trace:
+#0 {main}
+  thrown in %sh15903.php on line 4