ExtractPthread.Actionuniquely identifies the function call ** created/defined by `fun_ctx` function
type t = | Call of fun_call_id| Assign of string * string| Cond of string| ThreadCreate of thread| ThreadJoin of thread_id| ThreadExit| MutexInit of mutex_id| MutexLock of mutex_id| MutexUnlock of mutex_id| CondVarInit of cond_var_id| CondVarBroadcast of cond_var_id| CondVarSignal of cond_var_id| CondVarWait of cond_wait| NopADT of all possible edge actions types