[Bug]: Test regressions in 20250512.0 on i686

[musicinmybrain]

Describe the issue

On i686 (32-bit), starting with 20250512.0, absl_raw_hash_set_test and absl_stacktrace_test fail.

 60/218 Test  #61: absl_stacktrace_test ...............................***Failed    0.00 sec
Running main() from gmock_main.cc
[==========] Running 2 tests from 1 test suite.
[----------] Global test environment set-up.
[----------] 2 tests from StackTrace
[ RUN      ] StackTrace.FixupNoFixupEquivalence
/builddir/build/BUILD/abseil-cpp-20250512.0-build/abseil-cpp-20250512.0/absl/debugging/stacktrace_test.cc:126: Failure
Value of: absl::MakeSpan(a.result, static_cast<size_t>(a.depth))
Expected: equals {}
  Actual: { 0x5b18c483 }, which has these unexpected elements: 0x5b18c483

/builddir/build/BUILD/abseil-cpp-20250512.0-build/abseil-cpp-20250512.0/absl/debugging/stacktrace_test.cc:129: Failure
Value of: absl::MakeSpan(a.sizes, static_cast<size_t>(a.depth))
Expected: equals {}
  Actual: { 0 }, which has these unexpected elements: 0

[  FAILED  ] StackTrace.FixupNoFixupEquivalence (0 ms)
[ RUN      ] StackTrace.CanonicalFrameAddresses
[       OK ] StackTrace.CanonicalFrameAddresses (0 ms)
[----------] 2 tests from StackTrace (0 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test suite ran. (0 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] StackTrace.FixupNoFixupEquivalence

 1 FAILED TEST

[ RUN      ] Table.GrowExtremelyLargeTable
unknown file: Failure
C++ exception with description "std::bad_alloc" thrown in the test body.

[  FAILED  ] Table.GrowExtremelyLargeTable (836 ms)

Steps to reproduce the problem

Build abseil-cpp on i686 (or, probably, any 32-bit platform) and run the tests.

What version of Abseil are you using?

20250512.0

What operating system and version are you using?

Fedora Rawhide (observed while working on updating the system abseil-cpp package).

What compiler and version are you using?

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i686-redhat-linux/15/lto-wrapper
Target: i686-redhat-linux
Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,m2,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-libstdcxx-backtrace --with-libstdcxx-zoneinfo=/usr/share/zoneinfo --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-15.1.1-build/gcc-15.1.1-20250425/obj-i686-redhat-linux/isl-install --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch=i686 --build=i686-redhat-linux --with-build-config=bootstrap-lto --enable-link-serialization=1
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 15.1.1 20250425 (Red Hat 15.1.1-1) (GCC) 

What build system are you using?

cmake version 3.31.6

CMake suite maintained and supported by Kitware (kitware.com/cmake).

Additional context

No response

[musicinmybrain]

I opened #1888 for Table.GrowExtremelyLargeTable. The root cause of StackTrace.FixupNoFixupEquivalence is a little less obvious, and I’m just going to skip it downstream on i686 for now.