Revert "Revert "ART: Remove unnecessary SHARED_REQUIRES in ArtMethod""

This reverts commit 38b82870.

Do not always use ScopedObjectAccess. The GC might call this during
sanity checking, at which point the state is not runnable, but the
mutator lock is still held.

Currently needs an ugly NO_THREAD_SAFETY_ANALYSIS helper, as the
assert isn't correctly handled (establishing the held mutator lock).

Change-Id: Ie79e85e2afedc9b989382d88155b09e426fe7f75