Check pages are readable after mprotect for SEGV_ACCERR diagnosis

We have a suspected mprotect issue where we see seg faults after pages
are mprotected with PROT_READ|PROT_WRITE with the SS collector on
host. This change attempts to see if earlier reads would cause faults

Bug: 19894268

Change-Id: I041a663c6b55b747120915f73a0db5f566744ed8
3 files changed