Fix C23 label-at-end-of-compound-statement warnings

On non-free-threaded builds, Py_END_CRITICAL_SECTION() expands to just '}'.
When preceded by a goto label like 'cs_done:', this creates a C23 extension
that clang -Werror rejects. Adding an empty statement (;) after the label
makes it valid C11.

Author: rodrigobnogueira

multidict/_multidict.c

@@ -618,7 +618,7 @@ multidict_tp_init(MultiDictObject *self, PyObject *args, PyObject *kwds)
         goto cs_done;
     }
     ret = 0;
-cs_done:
+cs_done:;
     Py_END_CRITICAL_SECTION();
 done:
     Py_CLEAR(arg);
@@ -668,7 +668,7 @@ multidict_extend(MultiDictObject *self, PyObject *args, PyObject *kwds)
         failed = 1;
         goto cs_done;
     }
-cs_done:
+cs_done:;
     Py_END_CRITICAL_SECTION();
     Py_CLEAR(arg);
     if (failed) {
@@ -883,7 +883,7 @@ multidict_update(MultiDictObject *self, PyObject *args, PyObject *kwds)
         failed = 1;
         goto cs_done;
     }
-cs_done:
+cs_done:;
     Py_END_CRITICAL_SECTION();
     Py_CLEAR(arg);
     if (failed) {
@@ -915,7 +915,7 @@ multidict_merge(MultiDictObject *self, PyObject *args, PyObject *kwds)
         failed = 1;
         goto cs_done;
     }
-cs_done:
+cs_done:;
     Py_END_CRITICAL_SECTION();
     Py_CLEAR(arg);
     if (failed) {
@@ -1139,7 +1139,7 @@ cimultidict_tp_init(MultiDictObject *self, PyObject *args, PyObject *kwds)
         goto cs_done;
     }
     ret = 0;
-cs_done:
+cs_done:;
     Py_END_CRITICAL_SECTION();
 done:
     Py_CLEAR(arg);

multidict/_multilib/views.h

@@ -331,7 +331,7 @@ multidict_itemsview_and1(_Multidict_ViewObject *self, PyObject *other)
     if (PyErr_Occurred()) {
         failed = 1;
     }
-cs_done:
+cs_done:;
     if (failed) {
         md_finder_cleanup(&finder);
         Py_CLEAR(key2);
@@ -423,7 +423,7 @@ multidict_itemsview_and2(_Multidict_ViewObject *self, PyObject *other)
     if (PyErr_Occurred()) {
         failed = 1;
     }
-cs_done:
+cs_done:;
     if (failed) {
         md_finder_cleanup(&finder);
         Py_CLEAR(value2);
@@ -545,7 +545,7 @@ multidict_itemsview_or1(_Multidict_ViewObject *self, PyObject *other)
     if (PyErr_Occurred()) {
         failed = 1;
     }
-cs_done:
+cs_done:;
     if (failed) {
         md_finder_cleanup(&finder);
         Py_CLEAR(value2);
@@ -847,7 +847,7 @@ multidict_itemsview_sub2(_Multidict_ViewObject *self, PyObject *other)
     if (PyErr_Occurred()) {
         failed = 1;
     }
-cs_done:
+cs_done:;
     if (failed) {
         md_finder_cleanup(&finder);
         Py_CLEAR(value2);
@@ -1027,7 +1027,7 @@ multidict_itemsview_contains(_Multidict_ViewObject *self, PyObject *obj)
         goto cs_done;
     }
 
-cs_done:
+cs_done:;
     md_finder_cleanup(&finder);
     Py_END_CRITICAL_SECTION();
 done:
@@ -1095,7 +1095,7 @@ multidict_itemsview_isdisjoint(_Multidict_ViewObject *self, PyObject *other)
     if (PyErr_Occurred()) {
         failed = 1;
     }
-cs_done:
+cs_done:;
     md_finder_cleanup(&finder);
     Py_END_CRITICAL_SECTION();
     Py_CLEAR(iter);