Remove `ArtField::GetOffsetDCheck()`.

Similar to the `ArtField::GetAccessFlagsDCheck()` removed in
    https://android-review.googlesource.com/1982826 ,
remove the `ArtField::GetOffsetDCheck()` as the read barrier
when retrieving the declaring class may be undesirable in
some contexts and the check provides very little value.

Test: m test-art-host-gtest
Test: testrunner.py --host --optimizing
Bug: 181943478
Change-Id: I57e1c13855a1ce4f5fb3e1fe3e5187e3f794cea7
2 files changed