Fix elf.h typedef and ELFMAG, add IPPROTO_ICMPV6 and MSG_NOSIGNAL

src/header/sys_socket/constants.rs

@@ -139,6 +139,8 @@ pub const MSG_TRUNC: c_int = 32;
 pub const MSG_DONTWAIT: c_int = 64;
 /// Attempt to fill the read buffer.
 pub const MSG_WAITALL: c_int = 256;
+/// Do not generate SIGPIPE
+pub const MSG_NOSIGNAL: c_int = 0x4000;
 /// Atomically set the `FD_CLOEXEC` flag on any file descriptors created via
 /// `SCM_RIGHTS` during `recvmsg()`.
 pub const MSG_CMSG_CLOEXEC: c_int = 0x40000000;