Fix compiler warnings on "make android_arm"

src/compiler/js-operator.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_JS_OPERATOR_H_
 #define V8_COMPILER_JS_OPERATOR_H_
 
 #include "src/compiler/type-hints.h"
 #include "src/runtime/runtime.h"
 
@@ skipping 356 matching lines @@
 
 bool operator==(CreateLiteralParameters const&, CreateLiteralParameters const&);
 bool operator!=(CreateLiteralParameters const&, CreateLiteralParameters const&);
 
 size_t hash_value(CreateLiteralParameters const&);
 
 std::ostream& operator<<(std::ostream&, CreateLiteralParameters const&);
 
 const CreateLiteralParameters& CreateLiteralParametersOf(const Operator* op);
 
-const BinaryOperationHint BinaryOperationHintOf(const Operator* op);
+BinaryOperationHint BinaryOperationHintOf(const Operator* op);

[Jakob Kummerow, 2016/08/25 11:35:11]

../../src/compiler/js-operator.h:377:67: warning: type qualifiers ignored on
function return type [-Wignored-qualifiers]
 const BinaryOperationHint BinaryOperationHintOf(const Operator* op);
                                                                   ^

 
-const CompareOperationHint CompareOperationHintOf(const Operator* op);
+CompareOperationHint CompareOperationHintOf(const Operator* op);

[Jakob Kummerow, 2016/08/25 11:35:11]

../../src/compiler/js-operator.h:379:69: warning: type qualifiers ignored on
function return type [-Wignored-qualifiers]
 const CompareOperationHint CompareOperationHintOf(const Operator* op);
                                                                     ^

 
 // Interface for building JavaScript-level operators, e.g. directly from the
 // AST. Most operators have no parameters, thus can be globally shared for all
 // graphs.
 class JSOperatorBuilder final : public ZoneObject {
  public:
   explicit JSOperatorBuilder(Zone* zone);
 
   const Operator* Equal(CompareOperationHint hint);
   const Operator* NotEqual(CompareOperationHint hint);
@@ skipping 106 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(JSOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_OPERATOR_H_