Linux: Use in-tree copy of SO_ constants for !__USE_MISC [BZ #24532]

The kernel changes for a 64-bit time_t on 32-bit architectures
resulted in <asm/socket.h> indirectly including <linux/posix_types.h>.
The latter is not namespace-clean for the POSIX version of
<sys/socket.h>.

This issue has persisted across several Linux releases, so this commit
creates our own copy of the SO_* definitions for !__USE_MISC mode.

The new test socket/tst-socket-consts ensures that the copy is
consistent with the kernel definitions (which vary across
architectures).  The test is tricky to get right because CPPFLAGS
includes include/libc-symbols.h, which in turn defines _GNU_SOURCE
unconditionally.

Tested with build-many-glibcs.py.  I verified that a discrepancy in
the definitions actually results in a failure of the
socket/tst-socket-consts test.

1 files changed, 38 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/mips/bits/socket-constants.h b/sysdeps/unix/sysv/linux/mips/bits/socket-constants.h
new file mode 100644
index 0000000000..2c504499cb
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/mips/bits/socket-constants.h
@@ -0,0 +1,38 @@
+/* Socket constants which vary among Linux architectures.  Version for MIPS.
+   Copyright (C) 2019 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _SYS_SOCKET_H
+# error "Never include <bits/socket-constants.h> directly; use <sys/socket.h> instead."
+#endif
+
+#define SOL_SOCKET 65535
+#define SO_ACCEPTCONN 4105
+#define SO_BROADCAST 32
+#define SO_DONTROUTE 16
+#define SO_ERROR 4103
+#define SO_KEEPALIVE 8
+#define SO_LINGER 128
+#define SO_OOBINLINE 256
+#define SO_RCVBUF 4098
+#define SO_RCVLOWAT 4100
+#define SO_RCVTIMEO 4102
+#define SO_REUSEADDR 4
+#define SO_SNDBUF 4097
+#define SO_SNDLOWAT 4099
+#define SO_SNDTIMEO 4101
+#define SO_TYPE 4104