* calls.c (expand_call): Disallow sibcalls to noreturn functions.
        * flow.c (make_edges): Revert last change.

        * config/alpha/alpha.h (FUNCTION_OK_FOR_SIBCALL): Don't test
        TREE_THIS_VOLATILE.
        * config/pa/pa.h (FUNCTION_OK_FOR_SIBCALL): Likewise.

From-SVN: r36781