Revert^2 "X86: VarHandle.get() for reference type static fields."

This reverts commit 6a6cca588df43a180534db0b49475a8a5ab4c35a.

This commit extends the VarHandle.get() implementation to work with
reference type fields, not only primitive types.

Test: ART_HEAP_POISONING=true art/test.py --host --32 -r -t 712-varhandle-invocations
Bug: 65872996

Reason for revert: Fix loading the reference field.

Change-Id: Ide1f13fb9c6a4e97876862fb4772e9d543847f1f
3 files changed