gcc https://github.com/riscv-collab/riscv-gcc/tree/riscv-gcc-rvv-next/gcc/config/riscv
clang https://github.com/llvm/llvm-project/blob/main/clang/include/clang/Basic/riscv_vector.td
rvv https://github.com/riscv-non-isa/rvv-intrinsic-doc/blob/master/rvv-intrinsic-rfc.md

build error
felixonmars/archriscv-packages@0a6a736

• update gcc toolchain ci (https://zhuanlan.zhihu.com/p/492845064)
• add clang toolchain ci
• change word_type to size_t