Change well known boxing methods to `ArtMethod*`.

And make `ClassLinker::RunRootClinits()` responsible for
the initialization of primitive boxing classes.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Test: testrunner.py --host --interpreter --no-image
Bug: 253570082
Change-Id: Ia000113d53eb60518a137547684df28a0c788997
10 files changed