The commit fa5e9d72b0 ("Abstract POSIX filesystem functions") introduces
the build warning:
./core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c: In function ‘fd_object_release’:
./core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c:545:20: warning: this statement may fall through [-Wimplicit-fallthrough=]
545 | if (os_is_dir_stream_valid(&fo->directory.handle)) {
| ^
./core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c:549:13: note: here
549 | default:
| ^~~~~~~
Refer to the commit fb4afc7ca4 ("Apply clang-format for core/iwasm compilation and libraries"),
add one line "// Fallthrough." to make compiler happy.
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>