add upb_Map_Delete2()

We would like for upb_Map_Delete() to optionally return the deleted value.
Unfortunately this will require several steps since we are crossing repos.
Step #1: Add a new version of the function and point all local uses at it.

PiperOrigin-RevId: 497275930

lua/msg.c

@@ -579,7 +579,7 @@ static int lupb_Map_Newindex(lua_State* L) {
   upb_MessageValue key = lupb_tomsgval(L, lmap->key_type, 2, 1, LUPB_REF);
 
   if (lua_isnil(L, 3)) {
-    upb_Map_Delete(map, key);
+    upb_Map_Delete2(map, key, NULL);
   } else {
     upb_MessageValue val = lupb_tomsgval(L, lmap->value_type, 3, 1, LUPB_COPY);
     upb_Map_Set(map, key, val, lupb_Arenaget(L, 1));

python/map.c

@@ -182,7 +182,7 @@ int PyUpb_MapContainer_AssignSubscript(PyObject* _self, PyObject* key,
     if (!PyUpb_PyToUpb(val, val_f, &u_val, arena)) return -1;
     if (!PyUpb_MapContainer_Set(self, map, u_key, u_val, arena)) return -1;
   } else {
-    if (!upb_Map_Delete(map, u_key)) {
+    if (!upb_Map_Delete2(map, u_key, NULL)) {
       PyErr_Format(PyExc_KeyError, "Key not present in map");
       return -1;
     }

upb/collections/map.c

@@ -71,8 +71,12 @@ upb_MapInsertStatus upb_Map_Insert(upb_Map* map, upb_MessageValue key,
                                               map->val_size, arena);
 }
 
-bool upb_Map_Delete(upb_Map* map, upb_MessageValue key) {
-  return _upb_Map_Delete(map, &key, map->key_size);
+bool upb_Map_Delete2(upb_Map* map, upb_MessageValue key,
+                     upb_MessageValue* val) {
+  upb_value v;
+  const bool ok = _upb_Map_Delete(map, &key, map->key_size, &v);
+  if (val) val->uint64_val = v.val;
+  return ok;
 }
 
 bool upb_Map_Next(const upb_Map* map, upb_MessageValue* key,

upb/collections/map.h

@@ -76,7 +76,14 @@ UPB_INLINE bool upb_Map_Set(upb_Map* map, upb_MessageValue key,
 }
 
 // Deletes this key from the table. Returns true if the key was present.
-bool upb_Map_Delete(upb_Map* map, upb_MessageValue key);
+// If present and |val| is non-NULL, stores the deleted value.
+bool upb_Map_Delete2(upb_Map* map, upb_MessageValue key, upb_MessageValue* val);
+
+// Deletes this key from the table. Returns true if the key was present.
+// (DEPRECATED and going away soon. Do not use.)
+UPB_INLINE bool upb_Map_Delete(upb_Map* map, upb_MessageValue key) {
+  return upb_Map_Delete2(map, key, NULL);
+}
 
 // Map iteration:
 //

upb/collections/map_gencode_util.h

@@ -76,7 +76,7 @@ UPB_INLINE bool _upb_msg_map_delete(upb_Message* msg, size_t ofs,
                                     const void* key, size_t key_size) {
   upb_Map* map = *UPB_PTR_AT(msg, ofs, upb_Map*);
   if (!map) return false;
-  return _upb_Map_Delete(map, key, key_size);
+  return _upb_Map_Delete(map, key, key_size, NULL);
 }
 
 UPB_INLINE void _upb_msg_map_clear(upb_Message* msg, size_t ofs) {

upb/collections/map_internal.h

@@ -111,10 +111,10 @@ UPB_INLINE void _upb_Map_Clear(upb_Map* map) {
   upb_strtable_clear(&map->table);
 }
 
-UPB_INLINE bool _upb_Map_Delete(upb_Map* map, const void* key,
-                                size_t key_size) {
+UPB_INLINE bool _upb_Map_Delete(upb_Map* map, const void* key, size_t key_size,
+                                upb_value* val) {
   upb_StringView k = _upb_map_tokey(key, key_size);
-  return upb_strtable_remove2(&map->table, k.data, k.size, NULL);
+  return upb_strtable_remove2(&map->table, k.data, k.size, val);
 }
 
 UPB_INLINE bool _upb_Map_Get(const upb_Map* map, const void* key,