ART: Remove redundant MoveInstructionBefore method

Change-Id: If53d7011197cc6b9c1702a3d98ef11b59eb76f0c
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 150d6b0..ae3c4b0 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -785,22 +785,6 @@
   RemoveInstruction(initial);
 }
 
-void HBasicBlock::MoveInstructionBefore(HInstruction* insn, HInstruction* cursor) {
-  DCHECK(!cursor->IsPhi());
-  DCHECK(!insn->IsPhi());
-  DCHECK(!insn->IsControlFlow());
-  DCHECK(insn->CanBeMoved());
-  DCHECK(!insn->HasSideEffects());
-
-  HBasicBlock* from_block = insn->GetBlock();
-  HBasicBlock* to_block = cursor->GetBlock();
-  DCHECK(from_block != to_block);
-
-  from_block->RemoveInstruction(insn, /* ensure_safety */ false);
-  insn->SetBlock(to_block);
-  to_block->instructions_.InsertInstructionBefore(insn, cursor);
-}
-
 static void Add(HInstructionList* instruction_list,
                 HBasicBlock* block,
                 HInstruction* instruction) {
@@ -1352,6 +1336,11 @@
 }
 
 void HInstruction::MoveBefore(HInstruction* cursor) {
+  DCHECK(!IsPhi());
+  DCHECK(!IsControlFlow());
+  DCHECK(CanBeMoved());
+  DCHECK(!cursor->IsPhi());
+
   next_->previous_ = previous_;
   if (previous_ != nullptr) {
     previous_->next_ = next_;