Revert "Compile time null checks for VarHandle intrinsics."

This reverts commit b3a7a6a72d7b91ee5507bd7314a3aae3948e6f29.

Reason for revert: Breaks ART baseline compiler.

Bug: 191765508
Change-Id: Ida63660e0149c4847f015950f95282e61add7204
6 files changed