test: Correct outstanding -Werror=sign-compare errors

e.g.:
In file included from /usr/local/include/boost/test/test_tools.hpp:46:
/usr/local/include/boost/test/tools/old/impl.hpp:107:17: error: comparison of integers of different signs: 'const unsigned int' and 'const int' [-Werror,-Wsign-compare]
    return left == right;
           ~~~~ ^  ~~~~~
/usr/local/include/boost/test/tools/old/impl.hpp:130:16: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl<unsigned int, int>' requested here
        return equal_impl( left, right );
               ^
/usr/local/include/boost/test/tools/old/impl.hpp:145:16: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl_frwd::call_impl<unsigned int, int>' requested here
        return call_impl( left, right, left_is_array() );
               ^
/usr/local/include/boost/test/tools/old/impl.hpp:92:50: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl_frwd::operator()<unsigned int, int>' requested here
BOOST_PP_REPEAT( BOOST_TEST_MAX_PREDICATE_ARITY, IMPL_FRWD, _ )
                                                 ^
/usr/local/include/boost/preprocessor/repetition/repeat.hpp:30:26: note: expanded from macro 'BOOST_PP_REPEAT'
                         ^
/usr/local/include/boost/preprocessor/cat.hpp:22:32: note: expanded from macro 'BOOST_PP_CAT'
                               ^
/usr/local/include/boost/preprocessor/cat.hpp:29:34: note: expanded from macro 'BOOST_PP_CAT_I'
                                 ^
<scratch space>:153:1: note: expanded from here
BOOST_PP_REPEAT_1
^
test/streams_tests.cpp:122:5: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::check_frwd<boost::test_tools::tt_detail::equal_impl_frwd, unsigned int, int>' requested here
    BOOST_CHECK_EQUAL(varint, 54321);
    ^

/usr/local/include/boost/test/tools/old/impl.hpp:107:17: error: comparison of integers of different signs: 'const unsigned long long' and 'const long' [-Werror,-Wsign-compare]
    return left == right;
           ~~~~ ^  ~~~~~
/usr/local/include/boost/test/tools/old/impl.hpp:130:16: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl<unsigned long long, long>' requested here
        return equal_impl( left, right );
               ^
/usr/local/include/boost/test/tools/old/impl.hpp:145:16: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl_frwd::call_impl<unsigned long long, long>' requested here
        return call_impl( left, right, left_is_array() );
               ^
/usr/local/include/boost/test/tools/old/impl.hpp:92:50: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::equal_impl_frwd::operator()<unsigned long long, long>' requested here
BOOST_PP_REPEAT( BOOST_TEST_MAX_PREDICATE_ARITY, IMPL_FRWD, _ )
                                                 ^
/usr/local/include/boost/preprocessor/repetition/repeat.hpp:30:26: note: expanded from macro 'BOOST_PP_REPEAT'
                         ^
/usr/local/include/boost/preprocessor/cat.hpp:22:32: note: expanded from macro 'BOOST_PP_CAT'
                               ^
/usr/local/include/boost/preprocessor/cat.hpp:29:34: note: expanded from macro 'BOOST_PP_CAT_I'
                                 ^
<scratch space>:161:1: note: expanded from here
BOOST_PP_REPEAT_1
^
test/serfloat_tests.cpp:41:5: note: in instantiation of function template specialization 'boost::test_tools::tt_detail::check_frwd<boost::test_tools::tt_detail::equal_impl_frwd, unsigned long long, long>' requested here
    BOOST_CHECK_EQUAL(TestDouble(std::numeric_limits<double>::infinity()), 0x7ff0000000000000);
    ^

1 files changed, 4 insertions, 4 deletions

diff --git a/src/test/serfloat_tests.cpp b/src/test/serfloat_tests.cpp
index 54e07b0f61..7876c0bcda 100644
--- a/src/test/serfloat_tests.cpp
+++ b/src/test/serfloat_tests.cpp
@@ -36,9 +36,9 @@ uint64_t TestDouble(double f) {
 } // namespace
 
 BOOST_AUTO_TEST_CASE(double_serfloat_tests) {
-    BOOST_CHECK_EQUAL(TestDouble(0.0), 0);
+    BOOST_CHECK_EQUAL(TestDouble(0.0), 0U);
     BOOST_CHECK_EQUAL(TestDouble(-0.0), 0x8000000000000000);
-    BOOST_CHECK_EQUAL(TestDouble(std::numeric_limits<double>::infinity()), 0x7ff0000000000000);
+    BOOST_CHECK_EQUAL(TestDouble(std::numeric_limits<double>::infinity()), 0x7ff0000000000000U);
     BOOST_CHECK_EQUAL(TestDouble(-std::numeric_limits<double>::infinity()), 0xfff0000000000000);
     BOOST_CHECK_EQUAL(TestDouble(0.5), 0x3fe0000000000000ULL);
     BOOST_CHECK_EQUAL(TestDouble(1.0), 0x3ff0000000000000ULL);
@@ -48,8 +48,8 @@ BOOST_AUTO_TEST_CASE(double_serfloat_tests) {
 
     // Roundtrip test on IEC559-compatible systems
     if (std::numeric_limits<double>::is_iec559) {
-        BOOST_CHECK_EQUAL(sizeof(double), 8);
-        BOOST_CHECK_EQUAL(sizeof(uint64_t), 8);
+        BOOST_CHECK_EQUAL(sizeof(double), 8U);
+        BOOST_CHECK_EQUAL(sizeof(uint64_t), 8U);
         // Test extreme values
         TestDouble(std::numeric_limits<double>::min());
         TestDouble(-std::numeric_limits<double>::min());