CallGraph: Fix IgnoreAssumeLikeCalls option to Function::hasAddressTaken

This was added in 29e2d946 and likely never worked in a useful
way.

The test added for it fails when converted to opaque pointers, since
the lifetime intrinsic now directly uses the address. The code was
only trying to handle a user indirectly through a bitcast
instruction. That would never have been useful; a bitcast of a global
value would be folded to a ConstantExpr cast.

I also don't understand why it was special casing use_empty on the
cast. Relax the check to be either BitCastOperator or
AddrSpaceCastOperator. In practice, BitCastOperator won't appear
today.

I believe the change in parallel_deletion_cg_update is a correct
improvement but I didn't fully follow it. .omp_outlined..0 is used in
a constant expression cast to a call which ends up getting deleted.