Revert "[optimizing] Enable x86 long support."

Few libcore failures.

This reverts commit b4ba354cf8d22b261205494875cc014f18587b50.

Change-Id: I4a28d853e730dff9b69aec9555505803cf2fcd63
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 6945ff0..b7dd756 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -3289,19 +3289,8 @@
     if (kIsDebugBuild) {
       if (instruction != nullptr) {
         for (size_t i = 0, e = moves_.Size(); i < e; ++i) {
-          if (moves_.Get(i).GetInstruction() == instruction) {
-            // Special case the situation where the move is for the spill slot
-            // of the instruction.
-            if ((GetPrevious() == instruction)
-                || ((GetPrevious() == nullptr)
-                    && instruction->IsPhi()
-                    && instruction->GetBlock() == GetBlock())) {
-              DCHECK_NE(destination.GetKind(), moves_.Get(i).GetDestination().GetKind())
-                  << "Doing parallel moves for the same instruction.";
-            } else {
-              DCHECK(false) << "Doing parallel moves for the same instruction.";
-            }
-          }
+          DCHECK_NE(moves_.Get(i).GetInstruction(), instruction)
+            << "Doing parallel moves for the same instruction.";
         }
       }
       for (size_t i = 0, e = moves_.Size(); i < e; ++i) {