ART: Add VarHandle accessors to invoke-polymorphic entrypoint

Removes the need to interpret methods containing VarHandle accessor
methods. Whilst there are VarHandle accessors that the compiler does
not support, this will be the fallback path.

Bug: 71781600
Test: art/test.py --host -r -t 712
Change-Id: I40314b773882faed554c31b7f34c0e319dcf8d45