message: Update clang toolchain for RVV.
diff: @@ -17,8 +17,8 @@ set(CMAKE_ASM_COMPILER_TARGET ${CLANG_TARGET_TRIPLE})
  # Don't run the linker on compiler check
  set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
  -set(CMAKE_C_FLAGS "-march=rv64gcv0p10 -menable-experimental-extensions --gcc-toolchain=${RISCV_GCC_INSTALL_ROOT} -w ${CMAKE_C_FLAGS}")
  -set(CMAKE_CXX_FLAGS "-march=rv64gcv0p10 -menable-experimental-extensions --gcc-toolchain=${RISCV_GCC_INSTALL_ROOT} -w ${CXX_FLAGS}")
  +set(CMAKE_C_FLAGS "-march=rv64gcv --gcc-toolchain=${RISCV_GCC_INSTALL_ROOT} -w ${CMAKE_C_FLAGS}")
  +set(CMAKE_CXX_FLAGS "-march=rv64gcv --gcc-toolchain=${RISCV_GCC_INSTALL_ROOT} -w ${CXX_FLAGS}")
  set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -O2")
  set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
  