Remove unused IsNan function

test/cctest/test-double.cc

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "platform.h"
 #include "cctest.h"
 #include "diy-fp.h"
 #include "double.h"
@@ skipping 94 matching lines @@
   CHECK(!Double(OS::nan_value()).IsInfinite());
   CHECK(!Double(0.0).IsInfinite());
   CHECK(!Double(-0.0).IsInfinite());
   CHECK(!Double(1.0).IsInfinite());
   CHECK(!Double(-1.0).IsInfinite());
   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
   CHECK(!Double(min_double64).IsInfinite());
 }
 
 
-TEST(IsNan) {
-  CHECK(Double(OS::nan_value()).IsNan());
-  uint64_t other_nan = V8_2PART_UINT64_C(0xFFFFFFFF, 00000001);
-  CHECK(Double(other_nan).IsNan());
-  CHECK(!Double(V8_INFINITY).IsNan());
-  CHECK(!Double(-V8_INFINITY).IsNan());
-  CHECK(!Double(0.0).IsNan());
-  CHECK(!Double(-0.0).IsNan());
-  CHECK(!Double(1.0).IsNan());
-  CHECK(!Double(-1.0).IsNan());
-  uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
-  CHECK(!Double(min_double64).IsNan());
-}
-
-
 TEST(Sign) {
   CHECK_EQ(1, Double(1.0).Sign());
   CHECK_EQ(1, Double(V8_INFINITY).Sign());
   CHECK_EQ(-1, Double(-V8_INFINITY).Sign());
   CHECK_EQ(1, Double(0.0).Sign());
   CHECK_EQ(-1, Double(-0.0).Sign());
   uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
   CHECK_EQ(1, Double(min_double64).Sign());
 }
 
@@ skipping 71 matching lines @@
   Double d0(-4e-324);
   Double d1(d0.NextDouble());
   Double d2(d1.NextDouble());
   CHECK_EQ(-0.0, d1.value());
   CHECK_EQ(0.0, d2.value());
   CHECK_EQ(4e-324, d2.NextDouble());
   CHECK_EQ(-1.7976931348623157e308, Double(-V8_INFINITY).NextDouble());
   CHECK_EQ(V8_INFINITY,
            Double(V8_2PART_UINT64_C(0x7fefffff, ffffffff)).NextDouble());
 }