liblog: add __android_log_is_loggable()

- Add new liblog API __android_log_is_loggable(prio, tag, def)
- future plan to integrate this into the runtime checks and into
  the logd daemon for filtration. Inert for now.

Bug: 17760225
Change-Id: I16395b4d42acc08f0209f55a1cbf87b0b2112898
4 files changed
tree: b5eacc7f9bb508f8665b0b8eeb1242ba2e2f182d
  1. liblog/
  2. logcat/
  3. logd/
  4. logwrapper/