libgcc2.c (ia64_throw_helper): Use __builtin_return_address.

libgcc2.c (ia64_throw_helper): Use __builtin_return_address.

        * libgcc2.c (ia64_throw_helper): Use __builtin_return_address.
        (__throw): Don't pass the address of a label.

        * config/ia64/ia64.c (ia64_compute_frame_size): Use
        current_function_is_leaf.
        (ia64_expand_prologue): Likewise.  Modify return_address_pointer_rtx
        instead of reg_names[RETURN_ADDRESS_REGNUM].
        (ia64_init_machine_status): Reset return_address_pointer_rtx.
        * config/ia64/ia64.h (RETURN_ADDRESS_POINTER_REGNUM): Rename
        from RETURN_ADDRESS_REGNUM.  Update all uses.
        (RETURN_ADDR_RTX): Use return_address_pointer_rtx; return
        zero instead of null on failure.
        (ELIMINABLE_REGS): Add ra->b0 elimination.
        (CAN_ELIMINATE): Update accordingly.
        (INITIAL_ELIMINATION_OFFSET): Likewise.
        (REGISTER_NAMES): Use an illegal assembler name for
        RETURN_ADDRESS_POINTER_REGNUM.

From-SVN: r34531