Revert^2 "x86_64: Implement VarHandle.get{,Acquire,Opaque,Volatile} for byte array views."

This reverts commit 6620caa89a4691bc5cbdbc5af7599b17fd8896f5.

Reason for revert: Relanding original change after fixing linker error:
  ld.lld: error: undefined symbol: art::ObjPtr<art::mirror::Class>
       art::GetClassRoot<(art::ReadBarrierOption)0>(art::ClassRoot)

  The error was caused by a missing header which contained an `inline`
  definition of the above function. The error may or may not happen
  depending on the compiler: it may choose to not inline, and then there
  is no linker error.

Bug: 71781600
Test: Manually marked the function as always inline and ensured that the
  error can be reproduced and is fixed by including the header.
Change-Id: Ibcea2c3fc81ea75b8e6e6517d9ce872e79eda0d6
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index db0b9d7..3e601bb 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -488,6 +488,7 @@
 
   void LoadBootImageAddress(CpuRegister reg, uint32_t boot_image_reference);
   void LoadIntrinsicDeclaringClass(CpuRegister reg, HInvoke* invoke);
+  void LoadClassRootForIntrinsic(CpuRegister reg, ClassRoot class_root);
 
   void EmitLinkerPatches(ArenaVector<linker::LinkerPatch>* linker_patches) override;