Improve final/abstract methods in interfaces error messages

Closes #81683

Author: iluuu1994

Zend/tests/bug81683_1.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Bug #81683: Misleading "access type ... must be public" error message on final interface methods
+--FILE--
+<?php
+interface Foo {
+    public final function bar();
+}
+?>
+--EXPECTF--
+Fatal error: Interface method Foo::bar() must not be final in %s on line %d

Zend/tests/bug81683_2.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Bug #81683: Misleading "access type ... must be public" error message on abstract interface methods
+--FILE--
+<?php
+interface Foo {
+    public abstract function bar();
+}
+?>
+--EXPECTF--
+Fatal error: Interface method Foo::bar() must not be abstract in %s on line %d

Zend/zend_compile.c

@@ -7039,10 +7039,18 @@ static zend_string *zend_begin_method_decl(zend_op_array *op_array, zend_string
 	}
 
 	if (in_interface) {
-		if (!(fn_flags & ZEND_ACC_PUBLIC) || (fn_flags & (ZEND_ACC_FINAL|ZEND_ACC_ABSTRACT))) {
+		if (!(fn_flags & ZEND_ACC_PUBLIC)) {
 			zend_error_noreturn(E_COMPILE_ERROR, "Access type for interface method "
 				"%s::%s() must be public", ZSTR_VAL(ce->name), ZSTR_VAL(name));
 		}
+		if (fn_flags & ZEND_ACC_FINAL) {
+			zend_error_noreturn(E_COMPILE_ERROR, "Interface method "
+				"%s::%s() must not be final", ZSTR_VAL(ce->name), ZSTR_VAL(name));
+		}
+		if (fn_flags & ZEND_ACC_ABSTRACT) {
+			zend_error_noreturn(E_COMPILE_ERROR, "Interface method "
+				"%s::%s() must not be abstract", ZSTR_VAL(ce->name), ZSTR_VAL(name));
+		}
 		op_array->fn_flags |= ZEND_ACC_ABSTRACT;
 	}