RISC-V: Fix AVL/VL bug of VSETVL PASS[PR111548]

RISC-V: Fix AVL/VL bug of VSETVL PASS[PR111548]

This patch fixes that AVL/VL reg incorrect fetch in VSETVL PASS.

C/C++ regression passed.

But gfortran didn't run yet. I am still finding a way to run it.

Will commit it when I pass the fortran regression.

	PR target/111548

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (earliest_pred_can_be_fused_p): Bugfix

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/pr111548.c: New test.