Add thread_wait_list_end node for thread data and cond for Windows platform
to speedup the thread join and cond wait operations: no need to traverse the
wait list to get the end node to append the wait node.
This folder contains the platform abstract layer for multiple platforms. To support a new platform, you can simply create a new folder here and implement all the APIs defined in include folder.
Refer to port_wamr.md for how to port WAMR to a target platform.