Fix flaky tests on AArch64

Created by: fhahn

Currently, the following tests are flaky on some AArch64 hardware

 code_api|pthreads.pthreads_fork_FLAKY
 code_api|linux.sigsuspend
 code_api|pthreads.pthreads_exit
 code_api|security-common.TestMemProtChg_FLAKY
 code_api|pthreads.ptsig_FLAKY
 code_api|linux.fib-conflict
 code_api|linux.fib-conflict-early