Reimplement bdf0f24bb16d556a5b by checking for the caller' ABI in the implementation of PT_GET_SC_ARGS, and copying out everything if it is Linuxolator.
Also fix a minor information leak: if PT_GET_SC_ARGS_ALL is done on the thread reused after other process, it allows to read some number of that thread last syscall arguments. Clear td_sa.args in thread_alloc().