[kmp_tasking] segfault while benchmarking on AArch64

Hello,

I¹m experiencing a crash while using LLVM libomp from git master (SHA
306381bbdaf32d784487bbaf021c4acf68d68553). I¹m running taskwait_bench
benchmark from OpenMPTaskBench-1.0 on SoftIron board with 64-bit AMD
Opteron A1100 ARMv8 CPU: