As @richard.barton.arm observed at http://reviews.llvm.org/D12937#inline-107121 TargetParser in LLVM has insufficient support for ARMv6Z and ARMv6ZK.
In particular, there were no tests for TrustZone being supported in these architectures.
The patch clears a FIXME: left by @compnerd in r201471, and fixes his test case which hadn't really been testing what it was claiming to test.