aarch64: Improve epilogue unwind info

aarch64: Improve epilogue unwind info

        * config/aarch64/aarch64.c (aarch64_popwb_single_reg): Remove.
        (aarch64_popwb_pair_reg): Remove.
        (aarch64_set_frame_expr): Remove.
        (aarch64_restore_callee_saves): Add CFI_OPS argument; fill it with
        the restore ops performed by the insns generated.
        (aarch64_expand_epilogue): Attach CFI_OPS to the stack deallocation
        insn.  Perform the calls_eh_return addition later; do not attempt to
        preserve the CFA in that case.  Don't use aarch64_set_frame_expr.
        (aarch64_expand_prologue): Use REG_CFA_ADJUST_CFA directly, or no
        special markup at all.  Load cfun->machine->frame.hard_fp_offset
        into a local variable.
        (aarch64_frame_pointer_required): Don't check calls_alloca.

From-SVN: r214886