target/riscv: Remove pc_succ_insn from DisasContext

target/riscv: Remove pc_succ_insn from DisasContext

pc_succ_insn is no longer useful after the introduce of cur_insn_len
and all pc related value use diff value instead of absolute value.

Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20230526072124.298466-8-liweiwei@iscas.ac.cn>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>