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)
earch'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=e525c866d38b6c7498375f38eea7c92b0f7b6a4f'>root</a>/<a href='/guix/log/gnu?id=e525c866d38b6c7498375f38eea7c92b0f7b6a4f'>gnu</a>/<a href='/guix/log/gnu/tests?id=e525c866d38b6c7498375f38eea7c92b0f7b6a4f'>tests</a>/<a href='/guix/log/gnu/tests/reconfigure.scm?id=e525c866d38b6c7498375f38eea7c92b0f7b6a4f'>reconfigure.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/gnu/tests/reconfigure.scm?id=e525c866d38b6c7498375f38eea7c92b0f7b6a4f&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-02-09 23:16:45 +0100'>2020-02-09</span></td><td><a href='/guix/commit/gnu/tests/reconfigure.scm?id=e81344428726f3dae5d2a2e7bb296f46fcde6cc5'>Update e-mail address for Jakob L. Kreuze.</a><span class='msg-avail'>...<span class='msg-tooltip'>As requested here:
&lt;https://lists.gnu.org/archive/html/guix-devel/2020-02/msg00128.html&gt;.

* .mailmap: Add an entry for Jakob.
* gnu/machine.scm, gnu/machine/digital-ocean.scm, gnu/machine/ssh.scm,
gnu/packages/admin.scm, gnu/packages/i2p.scm, gnu/packages/music.scm,
gnu/packages/web.scm, gnu/tests/reconfigure.scm, guix/scripts/deploy.scm,
guix/scripts/system/reconfigure.scm: Update their e-mail address.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2019-08-07 15:27:09 -0400'>2019-08-07</span></td><td><a href='/guix/commit/gnu/tests/reconfigure.scm?id=ec12235ce207821027971c9d5f47b660b29f5ed5'>reconfigure: Improve tests for system activation.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/tests/reconfigure.scm (run-switch-to-system-test): Assert that
'/run/current-system' points to the activated system, and that new user
accounts specified in the operating system declaration are created.
</span></span></td><td>Jakob L. Kreuze</td></tr>
<tr><td><span title='2019-07-26 19:19:49 +0200'>2019-07-26</span></td><td><a href='/guix/commit/gnu/tests/reconfigure.scm?id=d23a00b599be56694065bd274184b9289fb8b85c'>tests: Add reconfigure system test.</a><span class='msg-avail'>...<span class='msg-tooltip'>[[PGP Signed Part:No public key for F506FD169D8FD95A created at 2019-07-24T18:35:10+0200 using RSA]]
* gnu/tests/reconfigure.scm: New file.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Jakob L. Kreuze</td></tr>