Refactor `Instrumentation` out of `Runtime`.

Avoid indirectly `#include`-ing `instrumentation.h` in every
compilation unit that needs the `runtime.h`. This reduces
incremental compilation times when touching certain files.

The additional load when accessing `Instrumentation` via the
`Runtime` has negligible performance impact.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Change-Id: Ibaf96696693b105e843c7c2cbf4e7604b126808e
19 files changed