Revert "Revert "Fully support pairs in the register allocator.""

This reverts commit c399fdc442db82dfda66e6c25518872ab0f1d24f.

Change-Id: I19f8215c4b98f2f0827e04bf7806c3ca439794e5
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 39ec22b..db89e68 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -663,7 +663,7 @@
     if (GetResultType() == Primitive::kPrimLong) {
       return new(GetBlock()->GetGraph()->GetArena()) HLongConstant(value);
     } else {
-      DCHECK(GetResultType() == Primitive::kPrimInt);
+      DCHECK_EQ(GetResultType(), Primitive::kPrimInt);
       return new(GetBlock()->GetGraph()->GetArena()) HIntConstant(value);
     }
   }