Improve is_instanceof inference

When a class is final, it may be treated as !is_instanceof.

Author: iluuu1994

Zend/Optimizer/zend_inference.c

@@ -2005,8 +2005,13 @@ static uint32_t get_ssa_alias_types(zend_ssa_alias_kind alias) {
 		if (var >= 0) {													\
 			if (ssa_var_info[var].ce != (_ce) ||                        \
 			    ssa_var_info[var].is_instanceof != (_is_instanceof)) {  \
-				ssa_var_info[var].ce = (_ce);						    \
-				ssa_var_info[var].is_instanceof = (_is_instanceof);     \
+				zend_class_entry *__ce = (_ce);							\
+				bool __is_instanceof = (_is_instanceof);				\
+				if (__ce && (__ce->ce_flags & ZEND_ACC_FINAL)) {		\
+					__is_instanceof = false;							\
+				}														\
+				ssa_var_info[var].ce = __ce;							\
+				ssa_var_info[var].is_instanceof = __is_instanceof;		\
 				if (update_worklist) { 									\
 					add_usages(op_array, ssa, worklist, var);			\
 				}														\