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 069d8d557de..c49c28c6e07 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.cc
@@ -1130,8 +1130,9 @@ CHECK_SIZE_AND_OFFSET(ipc_perm, cgid);
 #ifndef __GLIBC_PREREQ
 #define __GLIBC_PREREQ(x, y) 0
 #endif
-#if !defined(__aarch64__) || !SANITIZER_LINUX || __GLIBC_PREREQ (2, 21)
-/* On aarch64 glibc 2.20 and earlier provided incorrect mode field.  */
+#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
 
diff --git a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
index 304d04e3935..6dee89c97e1 100644
--- a/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
+++ b/libsanitizer/sanitizer_common/sanitizer_platform_limits_posix.h
@@ -207,20 +207,13 @@ namespace __sanitizer {
     unsigned long __unused1;
     unsigned long __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)

9ad5a2c73fb913cc8d1'>root</a>/<a href='/guix/log/doc?id=0495819926c09cd9dca5f9ad5a2c73fb913cc8d1'>doc</a>/<a href='/guix/log/doc/htmlxref.cnf?id=0495819926c09cd9dca5f9ad5a2c73fb913cc8d1'>htmlxref.cnf</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/doc/htmlxref.cnf?id=0495819926c09cd9dca5f9ad5a2c73fb913cc8d1&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-04-08 19:59:25 +0200'>2022-04-08</span></td><td><a href='/guix/commit/doc/htmlxref.cnf?id=868da34d54365023223a4ff7520043ba55ad64e8'>doc: Fix cookbook URLs in htmlxref.cnf.</a><span class='msg-avail'>...<span class='msg-tooltip'>Reported by Greg Hogan &lt;code@greghogan.com&gt;.

* doc/htmlxref.cnf (GUIX_ROOT): New variable.
(GUIX, GUIX_COOKBOOK): Adjust.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-10-04 16:36:58 +0200'>2021-10-04</span></td><td><a href='/guix/commit/doc/htmlxref.cnf?id=1267c2e9efdb6e324ce1c7b1fcef242f8208a61f'>doc: Update htmlxref.cnf.</a><span class='msg-avail'>...<span class='msg-tooltip'>Update and fix broken references to cuirass, git, and guix-cookbook.

* doc/htmlxref.cnf: Update from Texinfo.  Factorize Guix manuals.
(cuirass, git, guix-cookbook, guix-cookbook.de, guix-cookbook.fr): New
entries.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Sarah Morgensen</td></tr>
<tr><td><span title='2021-04-24 16:46:22 +0200'>2021-04-24</span></td><td><a href='/guix/commit/doc/htmlxref.cnf?id=1ebd086286c3825cfae31e75f8394986f1a18736'>doc: Fix cross-reference URL to translated manual.</a><span class='msg-avail'>...<span class='msg-tooltip'>* doc/htmlxref.cnf: Fix translated manual URL.
</span></span></td><td>Julien Lepiller</td></tr>