Fix for 689-zygote-jit-deopt on kernels before 3.11rc2

No JIT for zygote if cache flushes can signal faults. JIT for zygote
needs dual code mappings by design and the old kernel behaviour is
incompatible with this. The new test 689-zygote-jit-deopt was running
up against this issue on Nexus 6P test devices.

Test: art/test/testrunner/testrunner.py --target --64 -t 689
Bug: 136584457
Change-Id: Ibdafca270962d9e4a22ce1d9ba04f15771144899
2 files changed