RISC-V: Enable basic VLS modes support

Support && Test VLS modes load/store/reg move as well as LRA spilling

gcc/ChangeLog:

	* config/riscv/riscv-modes.def (VECTOR_BOOL_MODE): Add VLS modes.
	(ADJUST_ALIGNMENT): Ditto.
	(ADJUST_PRECISION): Ditto.
	(VLS_MODES): Ditto.
	(VECTOR_MODE_WITH_PREFIX): Ditto.
	* config/riscv/riscv-opts.h (TARGET_VECTOR_VLS): New macro.
	* config/riscv/riscv-protos.h (riscv_v_ext_vls_mode_p): New function.
	* config/riscv/riscv-v.cc (INCLUDE_ALGORITHM): Add include.
	(legitimize_move): Enable basic VLS modes support.
	(get_vlmul): Ditto.
	(get_ratio): Ditto.
	(get_vector_mode): Ditto.
	* config/riscv/riscv-vector-switch.def (VLS_ENTRY): Add vls modes.
	* config/riscv/riscv.cc (riscv_v_ext_vls_mode_p): New function.
	(VLS_ENTRY): New macro.
	(riscv_v_ext_mode_p): Add vls modes.
	(riscv_get_v_regno_alignment): New function.
	(riscv_print_operand): Add vls modes.
	(riscv_hard_regno_nregs): Ditto.
	(riscv_hard_regno_mode_ok): Ditto.
	(riscv_regmode_natural_size): Ditto.
	(riscv_vectorize_preferred_vector_alignment): Ditto.
	* config/riscv/riscv.md: Ditto.
	* config/riscv/vector-iterators.md: Ditto.
	* config/riscv/vector.md: Ditto.
	* config/riscv/autovec-vls.md: New file.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/partial/slp-9.c: Add more checks.
	* gcc.target/riscv/rvv/rvv.exp: Add VLS modes tests.
	* gcc.target/riscv/rvv/autovec/vls/def.h: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-1.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-10.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-11.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-12.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-13.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-14.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-15.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-16.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-17.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-2.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-3.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-4.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-5.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-6.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-7.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-8.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/mov-9.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-1.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-2.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-3.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-4.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-5.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-6.c: New test.
	* gcc.target/riscv/rvv/autovec/vls/spill-7.c: New test.