[BPF] Make BPFAbstractMemberAccessPass required

Or else on optnone functions we get the following during instruction selection:
  fatal error: error in backend: Cannot select: intrinsic %llvm.preserve.struct.access.index

Currently the -O0 pipeline doesn't properly run passes registered via
TargetMachine::registerPassBuilderCallbacks(), so don't add that RUN
line yet. That will be fixed after this.

Reviewed By: yonghong-song

Differential Revision: https://reviews.llvm.org/D89083