MIPS: Fix compilation failure for GCC5

test/unittests/compiler/typed-optimization-unittest.cc

Index: test/unittests/compiler/typed-optimization-unittest.cc
diff --git a/test/unittests/compiler/typed-optimization-unittest.cc b/test/unittests/compiler/typed-optimization-unittest.cc
index a895bb39483996cbd3089270f11348fe5af82b59..d73c72d4e021850758c8b4dc9214402572f1f630 100644
--- a/test/unittests/compiler/typed-optimization-unittest.cc
+++ b/test/unittests/compiler/typed-optimization-unittest.cc
@@ -56,9 +56,6 @@ const double kIntegerValues[] = {-V8_INFINITY, INT_MIN, -1000.0,  -42.0,
                                  -1.0,         0.0,     1.0,      42.0,
                                  1000.0,       INT_MAX, UINT_MAX, V8_INFINITY};
 
-Type* const kJSTypes[] = {Type::Undefined(), Type::Null(),   Type::Boolean(),
-                          Type::Number(),    Type::String(), Type::Object()};
-
 }  // namespace
 
 class TypedOptimizationTest : public TypedGraphTest {