Kernel+LibC: Move errno definitions to Kernel/API/POSIX

This fixes at least half of our LibC includes in the kernel. The source
of truth for errno codes and their description strings now lives in
Kernel/API/POSIX/errno.h as an enumeration, which LibC includes.

Userland/Libraries/LibC/errno_codes.h

@@ -0,0 +1,94 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/API/POSIX/errno.h>
+
+// NOTE: You can't define with a macro, so these have to be duplicated.
+#define EPERM EPERM
+#define ENOENT ENOENT
+#define ESRCH ESRCH
+#define EINTR EINTR
+#define EIO EIO
+#define ENXIO ENXIO
+#define E2BIG E2BIG
+#define ENOEXEC ENOEXEC
+#define EBADF EBADF
+#define ECHILD ECHILD
+#define EAGAIN EAGAIN
+#define ENOMEM ENOMEM
+#define EACCES EACCES
+#define EFAULT EFAULT
+#define ENOTBLK ENOTBLK
+#define EBUSY EBUSY
+#define EEXIST EEXIST
+#define EXDEV EXDEV
+#define ENODEV ENODEV
+#define ENOTDIR ENOTDIR
+#define EISDIR EISDIR
+#define EINVAL EINVAL
+#define ENFILE ENFILE
+#define EMFILE EMFILE
+#define ENOTTY ENOTTY
+#define ETXTBSY ETXTBSY
+#define EFBIG EFBIG
+#define ENOSPC ENOSPC
+#define ESPIPE ESPIPE
+#define EROFS EROFS
+#define EMLINK EMLINK
+#define EPIPE EPIPE
+#define ERANGE ERANGE
+#define ENAMETOOLONG ENAMETOOLONG
+#define ELOOP ELOOP
+#define EOVERFLOW EOVERFLOW
+#define EOPNOTSUPP EOPNOTSUPP
+#define ENOSYS ENOSYS
+#define ENOTIMPL ENOTIMPL
+#define EAFNOSUPPORT EAFNOSUPPORT
+#define ENOTSOCK ENOTSOCK
+#define EADDRINUSE EADDRINUSE
+#define EWHYTHO EWHYTHO
+#define ENOTEMPTY ENOTEMPTY
+#define EDOM EDOM
+#define ECONNREFUSED ECONNREFUSED
+#define EHOSTDOWN EHOSTDOWN
+#define EADDRNOTAVAIL EADDRNOTAVAIL
+#define EISCONN EISCONN
+#define ECONNABORTED ECONNABORTED
+#define EALREADY EALREADY
+#define ECONNRESET ECONNRESET
+#define EDESTADDRREQ EDESTADDRREQ
+#define EHOSTUNREACH EHOSTUNREACH
+#define EILSEQ EILSEQ
+#define EMSGSIZE EMSGSIZE
+#define ENETDOWN ENETDOWN
+#define ENETUNREACH ENETUNREACH
+#define ENETRESET ENETRESET
+#define ENOBUFS ENOBUFS
+#define ENOLCK ENOLCK
+#define ENOMSG ENOMSG
+#define ENOPROTOOPT ENOPROTOOPT
+#define ENOTCONN ENOTCONN
+#define ESHUTDOWN ESHUTDOWN
+#define ETOOMANYREFS ETOOMANYREFS
+#define EPROTONOSUPPORT EPROTONOSUPPORT
+#define ESOCKTNOSUPPORT ESOCKTNOSUPPORT
+#define EDEADLK EDEADLK
+#define ETIMEDOUT ETIMEDOUT
+#define EPROTOTYPE EPROTOTYPE
+#define EINPROGRESS EINPROGRESS
+#define ENOTHREAD ENOTHREAD
+#define EPROTO EPROTO
+#define ENOTSUP ENOTSUP
+#define EPFNOSUPPORT EPFNOSUPPORT
+#define EDQUOT EDQUOT
+#define EDIRINTOSELF EDIRINTOSELF
+#define ENOTRECOVERABLE ENOTRECOVERABLE
+#define EMAXERRNO EMAXERRNO
+
+#define EWOULDBLOCK EAGAIN
+#define ELAST EMAXERRNO