Fix issues on Android system builds
Fix issues on Android system builds

Bionic's implementation of strcmp() is hijacked by Honggfuzz, and invoked before
either Address Sanitizer or the trace-pc-guard coverage initialization routines
have been invoked.

This leads to segfaults on Android builds with ASAN+coverage.

Use trace_pc_guard as a convenient place to check for ASAN's initialization.
Defer trace_pc_guard activity until coverage is initialized.

Change-Id: I1dfa1946b8baad1ac58f39917d59b74ffd25bdd4

google/honggfuzz,google/honggfuzz,google/honggfuzz