Use the art dex file library to read the dex data.
Add unit tests for the UnwindDexFile code.
Bug: 72070049
Test: All unit tests continue to pass.
Test: Dumped the backtrace of the 137-cfi test while running in interpreter
Test: mode and verified that the stack trace is correct. Did this on host
Test: and for arm/arm64.
Change-Id: Ia6f343318c5dd6968a954015a7d59fdf101575b0
Christopher Ferris