RISC-V: Fix ICE in get_avl_or_vl_reg

RISC-V: Fix ICE in get_avl_or_vl_reg

update v1 -> v2: Add available fortran compiler check in rvv-fortran.exp.

This patch fix https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111395 ICE

update v2 -> v3: Remove redundant format.

	PR target/111395

gcc/ChangeLog:

	* config/riscv/riscv-vsetvl.cc (avl_info::operator==): Fix ICE.
	(vector_insn_info::global_merge): Ditto.
	(vector_insn_info::get_avl_or_vl_reg): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/fortran/pr111395.f90: New test.
	* gcc.target/riscv/rvv/rvv-fortran.exp: New test.