Merge branch 'PHP-7.4' into PHP-8.0

* PHP-7.4:
  Drop incorrect cache_slot optimization for typed properties

Author: nikic

Zend/tests/type_declarations/typed_properties_cache_slot_opt.phpt

@@ -0,0 +1,30 @@
+--TEST--
+Demonstrate that cache_slot optimization is illegal due to cache_slot merging
+--FILE--
+<?php
+
+class Test {
+    public int $prop;
+
+    public function method() {
+        // Opcache merges cache slots for both assignments.
+        $this->prop = 1;
+        try {
+            $this->prop = "foobar";
+        } catch (TypeError $e) {
+            echo $e->getMessage(), "\n";
+        }
+        var_dump($this->prop);
+    }
+}
+
+$test = new Test;
+$test->method();
+$test->method();
+
+?>
+--EXPECT--
+Cannot assign string to property Test::$prop of type int
+int(1)
+Cannot assign string to property Test::$prop of type int
+int(1)

Zend/zend_vm_def.h

@@ -2378,18 +2378,7 @@ ZEND_VM_C_LABEL(assign_object):
 				zend_property_info *prop_info = (zend_property_info*) CACHED_PTR_EX(cache_slot + 2);
 
 				if (UNEXPECTED(prop_info != NULL)) {
-					zend_uchar orig_type = IS_UNDEF;
-
-					if (OP_DATA_TYPE == IS_CONST) {
-						orig_type = Z_TYPE_P(value);
-					}
-
 					value = zend_assign_to_typed_prop(prop_info, property_val, value EXECUTE_DATA_CC);
-
-					/* will remain valid, thus no need to check prop_info in future here */
-					if (OP_DATA_TYPE == IS_CONST && Z_TYPE_P(value) == orig_type) {
-						CACHE_PTR_EX(cache_slot + 2, NULL);
-					}
 					ZEND_VM_C_GOTO(free_and_exit_assign_obj);
 				} else {
 ZEND_VM_C_LABEL(fast_assign_obj):