RISC-V: Fix wrong vsetvli fusion for vmv.s.x

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (reg_available_p): Fix bugs.
	(pass_vsetvl::compute_local_backward_infos): Fix bugs.
	(pass_vsetvl::need_vsetvl): Fix bugs.
	(pass_vsetvl::backward_demand_fusion): Fix bugs.
	(pass_vsetvl::demand_fusion): Fix bugs.
	(eliminate_insn): Fix bugs.
	(insert_vsetvl): Ditto.
	(pass_vsetvl::emit_local_forward_vsetvls): Ditto.
	* config/riscv/riscv-vsetvl.h (enum vsetvl_type): Ditto.
	* config/riscv/vector.md: Ditto.

gcc/testsuite/ChangeLog:

	* g++.target/riscv/rvv/base/bug-10.C: New test.
	* g++.target/riscv/rvv/base/bug-11.C: New test.
	* g++.target/riscv/rvv/base/bug-12.C: New test.
	* g++.target/riscv/rvv/base/bug-13.C: New test.
	* g++.target/riscv/rvv/base/bug-14.C: New test.
	* g++.target/riscv/rvv/base/bug-15.C: New test.
	* g++.target/riscv/rvv/base/bug-16.C: New test.
	* g++.target/riscv/rvv/base/bug-17.C: New test.
	* g++.target/riscv/rvv/base/bug-2.C: New test.
	* g++.target/riscv/rvv/base/bug-3.C: New test.
	* g++.target/riscv/rvv/base/bug-4.C: New test.
	* g++.target/riscv/rvv/base/bug-5.C: New test.
	* g++.target/riscv/rvv/base/bug-6.C: New test.
	* g++.target/riscv/rvv/base/bug-7.C: New test.
	* g++.target/riscv/rvv/base/bug-8.C: New test.
	* g++.target/riscv/rvv/base/bug-9.C: New test.

Signed-off-by: Ju-Zhe Zhong <juzhe.zhong@rivai.ai>
Co-authored-by: kito-cheng <kito.cheng@sifive.com>