RISC-V: Bugfix for RVV vbool*_t vn_reference_equal

RISC-V: Bugfix for RVV vbool*_t vn_reference_equal

In most architecture the precision_size of vbool*_t types are caculated
like as the multiple of the type size.  For example:
precision_size = type_size * 8 (aka, bit count per bytes).

Unfortunately, some architecture like RISC-V will adjust the
precision_size
for the vbool*_t in order to align the ISA. For example as below.
type_size      = [1, 1, 1, 1,  2,  4,  8]
precision_size = [1, 2, 4, 8, 16, 32, 64]

Then the precision_size of RISC-V vbool*_t will not be the multiple of
the
type_size. This PATCH try to enrich this case when comparing the
vn_reference.

Given we have the below code:
void test_vbool8_then_vbool16(int8_t * restrict in, int8_t * restrict
out) {
    vbool8_t v1 = *(vbool8_t*)in;
    vbool16_t v2 = *(vbool16_t*)in;

    *(vbool8_t*)(out + 100) = v1;
    *(vbool16_t*)(out + 200) = v2;
}

Before this PATCH:
csrr    t0,vlenb
slli    t1,t0,1
csrr    a3,vlenb
sub     sp,sp,t1
slli    a4,a3,1
add     a4,a4,sp
addi    a2,a1,100
vsetvli a5,zero,e8,m1,ta,ma
sub     a3,a4,a3
vlm.v   v24,0(a0)
vsm.v   v24,0(a2)
vsm.v   v24,0(a3)
addi    a1,a1,200
csrr    t0,vlenb
vsetvli a4,zero,e8,mf2,ta,ma
slli    t1,t0,1
vlm.v   v24,0(a3)
vsm.v   v24,0(a1)
add     sp,sp,t1
jr      ra

After this PATCH:
addi    a3,a1,100
vsetvli a4,zero,e8,m1,ta,ma
addi    a1,a1,200
vlm.v   v24,0(a0)
vsm.v   v24,0(a3)
vsetvli a5,zero,e8,mf2,ta,ma
vlm.v   v24,0(a0)
vsm.v   v24,0(a1)
ret

	PR target/109272

gcc/ChangeLog:

	* tree-ssa-sccvn.cc (vn_reference_eq): add type vector subparts
	check for vn_reference equal.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/base/pr108185-4.c: Update test check
	condition.
	* gcc.target/riscv/rvv/base/pr108185-5.c: Likewise.
	* gcc.target/riscv/rvv/base/pr108185-6.c: Likewise.

Signed-off-by: Pan Li <pan2.li@intel.com>