Clean up Class::FindStaticField().

Previously we have wrapped the class pointer in a Handle
for the GetDirectInterface() call but we didn't wrap the
DexCache pointer. Since GetDirectInferface() call from
this function cannot cause thread suspension anyway, fix
the inconsistency by using raw pointers where possible
and asserting that no thread suspension takes place.

Test: Run standard ART test suite in gcstress mode.
Change-Id: Ie4c6101aabd6fa68733e4920db277f835793d943
4 files changed