Fix SSA construction for ADD_ARRAY_ELEMENT in RC_INFERENCE mode

This was broken in cc29cbe.

Author: nikic

ext/opcache/Optimizer/zend_ssa.c

@@ -569,10 +569,6 @@ static int zend_ssa_rename(const zend_op_array *op_array, uint32_t build_flags,
 			}
 
 			switch (opline->opcode) {
-				case ZEND_ADD_ARRAY_UNPACK:
-				case ZEND_ADD_ARRAY_ELEMENT:
-					ssa_ops[k].result_use = var[EX_VAR_TO_NUM(opline->result.var)];
-					break;
 				case ZEND_ASSIGN:
 					if ((build_flags & ZEND_SSA_RC_INFERENCE) && opline->op2_type == IS_CV) {
 						ssa_ops[k].op2_def = ssa_vars_count;
@@ -718,6 +714,12 @@ static int zend_ssa_rename(const zend_op_array *op_array, uint32_t build_flags,
 						goto add_op1_def;
 					}
 					break;
+				case ZEND_ADD_ARRAY_UNPACK:
+					ssa_ops[k].result_use = var[EX_VAR_TO_NUM(opline->result.var)];
+					break;
+				case ZEND_ADD_ARRAY_ELEMENT:
+					ssa_ops[k].result_use = var[EX_VAR_TO_NUM(opline->result.var)];
+					/* break missing intentionally */
 				case ZEND_INIT_ARRAY:
 					if (((build_flags & ZEND_SSA_RC_INFERENCE)
 								|| (opline->extended_value & ZEND_ARRAY_ELEMENT_REF))

ext/opcache/tests/jit/array_elem.phpt

@@ -0,0 +1,28 @@
+--TEST--
+Refcount inference when adding array elements
+--FILE--
+<?php
+
+function test($a) {
+    $ary = [$a];
+    $ary2 = [0, $ary, $ary];
+    return $ary2;
+}
+var_dump(test(1));
+
+?>
+--EXPECT--
+array(3) {
+  [0]=>
+  int(0)
+  [1]=>
+  array(1) {
+    [0]=>
+    int(1)
+  }
+  [2]=>
+  array(1) {
+    [0]=>
+    int(1)
+  }
+}