Fix register allocation (missing store)

This fixes oss-fuzz #52022

Author: dstogov

ext/opcache/jit/zend_jit_trace.c

@@ -2428,6 +2428,7 @@ static zend_lifetime_interval** zend_jit_trace_allocate_registers(zend_jit_trace
 	const zend_ssa *op_array_ssa;
 	const zend_ssa_op *ssa_op;
 	int i, j, idx, count, level;
+	int last_idx = -1;
 	int *start, *end;
 	uint8_t *flags;
 	const zend_op_array **vars_op_array;
@@ -2831,6 +2832,7 @@ static zend_lifetime_interval** zend_jit_trace_allocate_registers(zend_jit_trace
 			}
 		}
 	} else {
+		last_idx = idx;
 		for (i = 0; i < op_array->last_var; i++) {
 			zend_jit_close_var(stack, i, start, end, flags, idx);
 		}
@@ -3140,6 +3142,14 @@ static zend_lifetime_interval** zend_jit_trace_allocate_registers(zend_jit_trace
 				}
 				phi = phi->next;
 			}
+		} else {
+			for (i = 0; i < ssa->vars_count; i++) {
+				if (intervals[i]
+				 && intervals[i]->range.end == last_idx
+				 && !(intervals[i]->flags & (ZREG_LOAD|ZREG_STORE))) {
+					intervals[i]->flags |= ZREG_STORE;
+				}
+			}
 		}
 
 		if (!count) {

ext/opcache/tests/jit/reg_alloc_017.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Register Alloction 017: Missing store
+--INI--
+opcache.enable=1
+opcache.enable_cli=1
+opcache.file_update_protection=0
+opcache.jit_buffer_size=1M
+--FILE--
+<?php
+function test() {
+    for($i = 0; $i < 10; $i++) {
+        $a = $b = $a + !$a = !$a;
+        $c = $c = $a;
+        $c % $a;
+    }
+}
+@test();
+?>
+DONE
+--EXPECT--
+DONE