RISC-V: Add testcases for form 1 of MASK_LEN_STRIDED_LOAD{STORE}

RISC-V: Add testcases for form 1 of MASK_LEN_STRIDED_LOAD{STORE}

Form 1:
  void __attribute__((noinline))                                        \
  vec_strided_load_store_##T##_form_1 (T *restrict out, T *restrict in, \
				       long stride, size_t size)        \
  {                                                                     \
    for (size_t i = 0; i < size; i++)                                   \
      out[i * stride] = in[i * stride];                                 \
  }

The below test suites are passed for this patch:
* The riscv fully regression test.

gcc/testsuite/ChangeLog:

	* gcc.target/riscv/rvv/rvv.exp: Add strided folder.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-f16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-f32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-f64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-i16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-i32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-i64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-i8.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-u16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-u32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-u64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-1-u8.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-f16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-f32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-f64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-i16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-i32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-i64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-i8.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-u16.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-u32.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-u64.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st-run-1-u8.c: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st.h: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st_data.h: New test.
	* gcc.target/riscv/rvv/autovec/strided/strided_ld_st_run.h: New test.

Signed-off-by: Pan Li <pan2.li@intel.com>
Co-Authored-By: Juzhe-Zhong <juzhe.zhong@rivai.ai>