Re #18521: fix not-quite-C syntax that works only because the PyXXX_Check are macros defined with () around them.

Modules/_ctypes/_ctypes.c

@@ -4202,7 +4202,7 @@ Array_subscript(PyObject *_self, PyObject *item)
             i += self->b_length;
         return Array_item(_self, i);
     }
-    else if PySlice_Check(item) {
+    else if (PySlice_Check(item)) {
         StgDictObject *stgdict, *itemdict;
         PyObject *proto;
         PyObject *np;

Modules/_testbuffer.c

@@ -1815,7 +1815,7 @@ ndarray_subscript(NDArrayObject *self, PyObject *key)
         if (init_slice(base, key, 0) < 0)
             goto err_occurred;
     }
-    else if PyTuple_Check(key) {
+    else if (PyTuple_Check(key)) {
         /* multi-dimensional slice */
         PyObject *tuple = key;
         Py_ssize_t i, n;