[PATCH] RISC-V: override alignment of function/jump/loop

Just like what AArch64 has done.

Signed-off-by: Wang Pengcheng <wangpengcheng.pp@bytedance.com>

gcc/ChangeLog:

	* config/riscv/riscv.cc (struct riscv_tune_param): Add new
	tune options.
	(riscv_override_options_internal): Override the default alignment
	when not optimizing for size.