Change MODE_BITSIZE to MODE_PRECISION for MODE_VECTOR_BOOL.

Change MODE_BITSIZE to MODE_PRECISION for MODE_VECTOR_BOOL.

RISC-V lowers the TYPE_PRECISION for MODE_VECTOR_BOOL vectors in order
to distinguish between VNx1BI, VNx2BI, VNx4BI and VNx8BI.

This patch adjusts uses of MODE_VECTOR_BOOL to use GET_MODE_PRECISION
instead of GET_MODE_BITSIZE.

The RISC-V tests are provided by Juzhe.

Co-Authored-By: Juzhe-Zhong <juzhe.zhong@rivai.ai>
gcc/c-family/ChangeLog:

	* c-common.cc (c_common_type_for_mode): Use GET_MODE_PRECISION.

gcc/ChangeLog:

	* simplify-rtx.cc (native_encode_rtx): Ditto.
	(native_decode_vector_rtx): Ditto.
	(simplify_const_vector_byte_offset): Ditto.
	(simplify_const_vector_subreg): Ditto.
	* tree.cc (build_truth_vector_type_for_mode): Ditto.
	* varasm.cc (output_constant_pool_2): Ditto.

gcc/fortran/ChangeLog:

	* trans-types.cc (gfc_type_for_mode): Ditto.

gcc/go/ChangeLog:

	* go-lang.cc (go_langhook_type_for_mode): Ditto.

gcc/lto/ChangeLog:

	* lto-lang.cc (lto_type_for_mode): Ditto.

gcc/rust/ChangeLog:

	* backend/rust-tree.cc (c_common_type_for_mode): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-1.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-10.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-11.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-12.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-13.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-14.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-2.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-3.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-4.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-5.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-6.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-7.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-8.c: New test.
	* gcc.target/riscv/rvv/autovec/vls-vlmax/bitmask-9.c: New test.