The TLS_SLOT_TSAN slot is available starting in N, but its location (8)
is incompatible with the proposed solution for implementing ELF TLS on
Android (i.e. bump ARM/AArch64 alignment to reserve an 8-word TCB).
Instead, starting in Q, Bionic replaced TLS_SLOT_DLERROR(6) with
TLS_SLOT_SANITIZER(6). Switch compiler-rt to the new slot.