Revert "Implement long negate instruction in the optimizing compiler."

This reverts commit 66ce173a40eff4392e9949ede169ccf3108be2db.
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 5edf0f0..7b00d2f 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -1043,13 +1043,11 @@
       new (GetGraph()->GetArena()) LocationSummary(neg, LocationSummary::kNoCall);
   switch (neg->GetResultType()) {
     case Primitive::kPrimInt:
-    case Primitive::kPrimLong: {
-      bool output_overlaps = (neg->GetResultType() == Primitive::kPrimLong);
       locations->SetInAt(0, Location::RequiresRegister());
-      locations->SetOut(Location::RequiresRegister(), output_overlaps);
+      locations->SetOut(Location::RequiresRegister());
       break;
-    }
 
+    case Primitive::kPrimLong:
     case Primitive::kPrimFloat:
     case Primitive::kPrimDouble:
       LOG(FATAL) << "Not yet implemented neg type " << neg->GetResultType();
@@ -1071,15 +1069,6 @@
       break;
 
     case Primitive::kPrimLong:
-      DCHECK(in.IsRegisterPair());
-      __ rsbs(out.AsRegisterPairLow<Register>(),
-              in.AsRegisterPairLow<Register>(),
-              ShifterOperand(0));
-      __ rsc(out.AsRegisterPairHigh<Register>(),
-             in.AsRegisterPairHigh<Register>(),
-             ShifterOperand(0));
-      break;
-
     case Primitive::kPrimFloat:
     case Primitive::kPrimDouble:
       LOG(FATAL) << "Not yet implemented neg type " << neg->GetResultType();