Rewrite test CHECK to work on all platforms, including MIPS

R=jkummerow@chromium.org

Review URL: https://chromiumcodereview.appspot.com/9536005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10867 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/test-api.cc

@@ -12910,7 +12910,7 @@ static void ExternalArrayTestHelper(v8::ExternalArrayType array_type,
   if (array_type == v8::kExternalDoubleArray ||
       array_type == v8::kExternalFloatArray) {
     CHECK_EQ(
-        static_cast<int>(0x80000000),
+        static_cast<int>(i::OS::nan_value()),
         static_cast<int>(jsobj->GetElement(7)->ToObjectChecked()->Number()));
   } else {
     CHECK_EQ(0, static_cast<int>(