Fixed compilation of match with undefined input

Fixes oss-fuzz #63542

Author: dstogov

ext/opcache/jit/zend_jit_ir.c

@@ -15549,9 +15549,13 @@ static int zend_jit_switch(zend_jit_ctx *jit, const zend_op *opline, const zend_
 				ir_MERGE_list(continue_list);
 			} else {
 				if (default_input_list) {
-					ZEND_ASSERT(jit->ctx.ir_base[ref].op == IR_SWITCH);
-					ZEND_ASSERT(jit->ctx.ir_base[ref].op3 == IR_UNUSED);
-					jit->ctx.ir_base[ref].op3 = default_input_list;
+					if (jit->ctx.ir_base[ref].op == IR_SWITCH) {
+						ZEND_ASSERT(jit->ctx.ir_base[ref].op3 == IR_UNUSED);
+						jit->ctx.ir_base[ref].op3 = default_input_list;
+					} else {
+						ir_MERGE_list(default_input_list);
+						_zend_jit_add_predecessor_ref(jit, default_b, jit->b, ir_END());
+					}
 				}
 				jit->b = -1;
 			}

ext/opcache/tests/jit/match_001.phpt

@@ -0,0 +1,22 @@
+--TEST--
+Match with undefined input
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_update_protection=0
+opcache.jit_buffer_size=1M
+--FILE--
+<?php
+function foo() {
+    return match($y){1,6=>0};
+}
+foo();
+?>
+--EXPECTF--
+Warning: Undefined variable $y in %smatch_001.php on line 3
+
+Fatal error: Uncaught UnhandledMatchError: Unhandled match case NULL in %smatch_001.php:3
+Stack trace:
+#0 %smatch_001.php(5): foo()
+#1 {main}
+  thrown in %smatch_001.php on line 3