RISC-V: Bugfix for max_sew_overlap_and_next_ratio_valid_for_prev_sew_p[pr117483]

RISC-V: Bugfix for max_sew_overlap_and_next_ratio_valid_for_prev_sew_p[pr117483]

This patch fixs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117483

If prev and next satisfy the following rules, we should forbid the case
(next.get_sew() < prev.get_sew() && (!next.get_ta() || !next.get_ma()))
in the compatible function max_sew_overlap_and_next_ratio_valid_for_prev_sew_p.
Otherwise, the tail elements of next will be polluted.

DEF_SEW_LMUL_RULE (ge_sew, ratio_and_ge_sew, ratio_and_ge_sew,
 max_sew_overlap_and_next_ratio_valid_for_prev_sew_p,
 always_false, use_max_sew_and_lmul_with_next_ratio)

Passed the rv64gcv full regression test.

Signed-off-by: Li Xu <xuli1@eswincomputing.com>
	PR target/117483

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc: Fix bug.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/pr117483.c: New test.