Fix assertion failure in libsanitizer when using glibc 2.31 and later.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92154
https://reviews.llvm.org/D69104

Adapted from these upstream revision:

https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=277981
https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=279653

diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
index 196eb3b3c64..b588e07e5ab 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -928,7 +928,11 @@ CHECK_SIZE_AND_OFFSET(ipc_perm, uid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, gid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cuid);
 CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
+#if !SANITIZER_LINUX || __GLIBC_PREREQ (2, 31)
+/* glibc 2.30 and earlier provided 16-bit mode field instead of 32-bit
+   on many architectures.  */
 CHECK_SIZE_AND_OFFSET(ipc_perm, mode);
+#endif
 CHECK_SIZE_AND_OFFSET(ipc_perm, __seq);
 
 CHECK_TYPE_SIZE(shmid_ds);
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
index aec950454b3..6d94fc65c28 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -154,20 +154,13 @@ namespace __sanitizer {
     u64 __unused1;
     u64 __unused2;
 #elif defined(__sparc__)
-# if defined(__arch64__)
     unsigned mode;
-    unsigned short __pad1;
-# else
-    unsigned short __pad1;
-    unsigned short mode;
     unsigned short __pad2;
-# endif
     unsigned short __seq;
     unsigned long long __unused1;
     unsigned long long __unused2;
 #else
-    unsigned short mode;
-    unsigned short __pad1;
+    unsigned int mode;
     unsigned short __seq;
     unsigned short __pad2;
 #if defined(__x86_64__) && !defined(_LP64)
ath'>path: <a href='/guix/log/?id=b0e224566f2ca6b8d375c89f8d023e1b836f31e4'>root</a>/<a href='/guix/log/tests?id=b0e224566f2ca6b8d375c89f8d023e1b836f31e4'>tests</a>/<a href='/guix/log/tests/accounts.scm?id=b0e224566f2ca6b8d375c89f8d023e1b836f31e4'>accounts.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/accounts.scm?id=b0e224566f2ca6b8d375c89f8d023e1b836f31e4&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-08-28 00:27:14 +0200'>2019-08-28</span></td><td><a href='/guix/commit/tests/accounts.scm?id=dd4e46edda6c255ca170a6650c6f92b16ff50a3f'>accounts: Delete duplicate entries.</a><span class='msg-avail'>...<span class='msg-tooltip'>When adding multiple instances of a service requiring some user
account/group, we could end up with multiple entries for that account or
group in /etc/passwd or /etc/group.

* gnu/build/accounts.scm (database-writer)[write-entries]: Add call to
'delete-duplicates'.
* tests/accounts.scm ("write-passwd with duplicate entry"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-04-27 16:30:40 +0200'>2019-04-27</span></td><td><a href='/guix/commit/tests/accounts.scm?id=0c329bf4b0c00abdc9a7d9c818d36d4d60b3005d'>tests: Adjust accounts test to shell-as-config change.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 504a0fc636ec591e65b4a229a37e522e425d8a0c.

* tests/accounts.scm ("allocate-passwd with previous state"): Change
expected 'shell' for "alice" to "/bin/sh".
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-03-25 23:37:06 +0100'>2019-03-25</span></td><td><a href='/guix/commit/tests/accounts.scm?id=cf848cc0a17a3a58d600116896f6e7abfb0440d4'>accounts: Add default value for the 'home-directory' field of &lt;user-account&gt;.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/accounts.scm (&lt;user-account&gt;)[home-directory]: Mark as
thunked and add a default value.
(default-home-directory): New procedure.
* doc/guix.texi (User Accounts): Remove 'home-directory' from example.
* gnu/system/examples/bare-bones.tmpl: Likewise.
* gnu/system/examples/beaglebone-black.tmpl: Likewise.
* gnu/system/examples/desktop.tmpl: Likewise.
* gnu/system/examples/docker-image.tmpl: Likewise.
* gnu/system/examples/lightweight-desktop.tmpl: Likewise.
* gnu/system/install.scm (installation-os): Likewise.
* gnu/tests.scm (%simple-os): Likewise.
* gnu/tests/install.scm (%minimal-os, %minimal-os-on-vda):
(%separate-home-os, %encrypted-root-os, %btrfs-root-os): Likewise.
* tests/accounts.scm ("allocate-passwd")
("allocate-passwd with previous state"): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-03-07 20:05:09 +0100'>2019-03-07</span></td><td><a href='/guix/commit/tests/accounts.scm?id=ec600e4544729f1aaf46fa5162bba334515d0de5'>Add (gnu build accounts).</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/accounts.scm, tests/accounts.scm: New files.
* Makefile.am (SCM_TESTS): Add tests/accounts.scm.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add build/accounts.scm.
</span></span></td><td>Ludovic Courtès</td></tr>