This function finishes the definition of a buffer save group.
You must have previously called the function buffer_async_group_begin()
to initiate the group, then call the function buffer_save_async() for each
file that you wish to save out. Finally you call this function,
which will start the saving of the files.
save1 = buffer_save_async(buff1, "Player_Save1.sav", 0, 16384);
save2 = buffer_save_async(buff2, "Player_Save2.sav", 0, 16384);
save3 = buffer_save_async(buff3, "Player_Save3.sav", 0, 16384);
save4 = buffer_save_async(buff4, "Player_Save4.sav", 0, 16384);
The above code starts a buffer group then sets it to save out 4 files asynchronously. The group definition is then ended (at which point saving will begin).