add missing socket constants

libc-test/build.rs

src/unix/bsd/apple/mod.rs

src/unix/bsd/freebsdlike/mod.rs

src/unix/bsd/mod.rs

src/unix/bsd/netbsdlike/mod.rs

src/unix/haiku/mod.rs

src/unix/mod.rs

src/unix/notbsd/android/mod.rs

src/unix/notbsd/linux/mips/mod.rs

src/unix/notbsd/linux/other/b64/aarch64.rs

src/unix/notbsd/linux/other/b64/powerpc64.rs

src/unix/notbsd/linux/other/b64/x86_64.rs

src/unix/notbsd/mod.rs

src/unix/solaris/mod.rs

src/unix/uclibc/mod.rs