Add -Xcheck:jni.

I think this is as complete as possible right now. The remaining
two #if 0 sections require:

1. a way to get the Method* of the current native method.
2. a way to get the Class* of the type of a given Field*.

Change-Id: I331586022095fb36ccc10c9ac1890a59a9224d01
14 files changed
tree: 3f72ceee0297d213dac66a9ce2c72592906c1803
  2. build/
  3. src/
  4. test/
  5. tools/