RISC-V: Fix incorrect demand info merge in local vsetvli optimization [PR109748]

RISC-V: Fix incorrect demand info merge in local vsetvli optimization [PR109748]

This patch is fixing my recent optimization patch:
https://github.com/gcc-mirror/gcc/commit/d51f2456ee51bd59a79b4725ca0e488c25260bbf

In that patch, the new_info = parse_insn (i) is not correct.
Since consider the following case:

vsetvli a5,a4, e8,m1
..
vsetvli zero,a5, e32, m4
vle8.v
vmacc.vv
...

Since we have backward demand fusion in Phase 1, so the real demand of "vle8.v" is e32, m4.
However, if we use parse_insn (vle8.v) = e8, m1 which is not correct.

So this patch we change new_info = new_info.parse_insn (i)
into:

vector_insn_info new_info = m_vector_manager->vector_insn_infos[i->uid ()];

So that, we can correctly optimize codes into:

vsetvli a5,a4, e32, m4
..
.. (vsetvli zero,a5, e32, m4 is removed)
vle8.v
vmacc.vv

Since m_vector_manager->vector_insn_infos is the member variable of pass_vsetvl class.
We remove static void function "local_eliminate_vsetvl_insn", and make it as the member function
of pass_vsetvl class.

	PR target/109748

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (local_eliminate_vsetvl_insn): Remove it.
	(pass_vsetvl::local_eliminate_vsetvl_insn): New function.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/vsetvl/pr109748.c: New test.