'pcall' and 'xpcall' that allow calls to 'coroutine.yield', including support for a 'debug.traceback' that show the correct stack trace of the functions executed using these functions. remove depedency of global variables, so the functions of module 'compat52' work even when the global functions are absent.
'pcall' and 'xpcall' that allow calls to 'coroutine.yield', including support for a 'debug.traceback' that show the correct stack trace of the functions executed using these functions.
remove depedency of global variables, so the functions of module 'compat52' work even when the global functions are absent.

keplerproject/lua-compat-5.2