Support using opaque JNI ids

Currently JNI ids (jmethodID &  jfieldID) are created by simply
casting the corresponding ART structure pointer. This is great for
simplicity but means we are prevented from performing operations that
could change these pointer values. To support these use-cases add
support for loading the runtime with a layer of indirection between
these ids and the internal art data types.

Currently the JNI id type can be toggled only by passing the new
'-Xopaque-jni-ids:{true,false}' flag during startup.

This changes the --debuggable test configuration to pass
'-Xopaque-jni-ids:true' in order to get test coverage of this feature
using the 'art-jit' configuration.

Test: ./test.py --host --debuggable
Test: ./test.py --host --debuggable --jit-on-first-use
Test: ./test/testrunnner/run_build_test_target.py art-jit
Bug: 134162467
Change-Id: Id8c8cb9a5b8ff18dc2f40892fae2d344a7214f44
23 files changed