This fixes a buildbot breakage (e.g.,
https://lab.llvm.org/buildbot/#/builders/77/builds/31422/steps/21/logs/stdio)
that was caused by the introduction of this test
(ff1329e297).
Build error from buildbot:
/var/lib/buildbot/sanitizer-buildbot6/sanitizer-x86_64-linux-android/build/llvm-project/compiler-rt/test/hwasan/TestCases/bcmp.cpp:18:10: error: use of undeclared identifier 'bcmp'
18 | return bcmp(p, a, size);
