This patch re-enabled GWP-ASan for Android and other ARM platforms. It does two
- Adds -fno-emulated-tls, as the clang driver still default compiles using emulated TLS on Android.
- Also uses sanitizer common unwinder on Android, as glibc backtrace() isn't available.
This patch should be monitored closely when submitting. I don't have the ARM32
machines that the patches initially broke to verify that this fixes the
problem, but it's a good attempt.