clang -O2   -Wall -Wextra -Werror=implicit-function-declaration fcntl/posix_fadvise.c -o fcntl/posix_fadvise -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE  -lm   -lintl
../out/minix/basic/fcntl/posix_fadvise.o: In function `main':
fcntl/posix_fadvise.c:(.text+0x33f): undefined reference to `posix_fadvise'
clang: error: linker command failed with exit code 1 (use -v to see invocation)