Solved issue 54168
This commit divides the large test files(over 30k lines) under clang/test/CodeGen/RISCV including:
- rvv-intrinsics/vloxseg.c
- rvv-intrinsics/vluxseg.c
- rvv-intrinsics-overloaded/vloxseg.c
- rvv-intrinsics-overloaded/vluxseg.c
into "non-masked" version and "masked" version which can reduce the test cases by 50% in a single file.