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)
input type='submit' value='search'/>
</form>
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<div class='path'>path: <a href='/guix/log/?id=053b10c3ef2df7ea80556ab9b2c93d0bf88094f2'>root</a>/<a href='/guix/log/tests?id=053b10c3ef2df7ea80556ab9b2c93d0bf88094f2'>tests</a>/<a href='/guix/log/tests/guix-package-aliases.sh?id=053b10c3ef2df7ea80556ab9b2c93d0bf88094f2'>guix-package-aliases.sh</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/guix-package-aliases.sh?id=053b10c3ef2df7ea80556ab9b2c93d0bf88094f2&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-09-21 16:48:36 +0200'>2019-09-21</span></td><td><a href='/guix/commit/tests/guix-package-aliases.sh?id=660dbe65641851aa99b810e4ae065a5f72dc37d0'>guix package: '--show' ignores deprecated packages.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-09-21 16:48:36 +0200'>2019-09-21</span></td><td><a href='/guix/commit/tests/guix-package-aliases.sh?id=aeb51370da7c854e8167066df9b138e15d7363e6'>guix package: Add 'guix show' alias.</a><span class='msg-avail'>...</span></td><td>zimoun</td></tr>
<tr><td><span title='2019-04-29 12:19:24 +0200'>2019-04-29</span></td><td><a href='/guix/commit/tests/guix-package-aliases.sh?id=da56f10971e0b6f32969b10e38ed043b2c99bb82'>guix package: Add 'guix search' alias.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-04-29 10:13:44 +0200'>2019-04-29</span></td><td><a href='/guix/commit/tests/guix-package-aliases.sh?id=d824cfbabeb0780c9ea7a6dab02c47b6a4d029c6'>guix package: Add 'install', 'remove', and 'upgrade' aliases.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>