* eval.c (xsignal): New func. Like Fsignal, but marked no-return.

* eval.c (xsignal): New func.  Like Fsignal, but marked no-return.
(xsignal0, xsignal1, xsignal2, xsignal3): New no-return functions.
(signal_error): New no-return function (from xfaces.c).
(Fthrow): Use xsignal2 instead of Fsignal + abort.
(error): Use xsignal1 instead of Fsignal + abort.
(FletX, Flet, grow_specpdl): Use signal_error.
(Feval, Ffuncall, funcall_lambda): Use xsignal1, xsignal2.

* xfaces.c (signal_error): Move to eval.c.
(resolve_face_name): Use xsignal1.