Remove duplicated wasi_dircookie_t typedef in libc_wasi_wrapper.h (#808)
Remove duplicated wasi_dircookie_t typedef in libc_wasi_wrapper.h (#808)

Remove duplicated wasi_dircookie_t typedef in libc_wasi_wrapper.h to
fix clang warnings.
bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime