Fix android debug build.

src/compiler/gap-resolver.cc

Index: src/compiler/gap-resolver.cc
diff --git a/src/compiler/gap-resolver.cc b/src/compiler/gap-resolver.cc
index bc151c2c305efbfc5fb6a41031c350c8a240f1ea..a8dbbc0f79956e29b02eeeb274066e375603e55f 100644
--- a/src/compiler/gap-resolver.cc
+++ b/src/compiler/gap-resolver.cc
@@ -17,7 +17,8 @@ typedef ZoneList<MoveOperands>::iterator op_iterator;
 #ifdef ENABLE_SLOW_ASSERTS
 // TODO(svenpanne) Brush up InstructionOperand with comparison?
 struct InstructionOperandComparator {
-  bool operator()(const InstructionOperand* x, const InstructionOperand* y) {
+  bool operator()(const InstructionOperand* x,
+                  const InstructionOperand* y) const {
     return (x->kind() < y->kind()) ||
            (x->kind() == y->kind() && x->index() < y->index());
   }