Fix _addcarry_u64 macro for MSVC

Author: mborland

include/boost/decimal/detail/config.hpp

@@ -85,6 +85,11 @@
 #  else
 #    define BOOST_DECIMAL_HAS_MSVC_32BIT_INTRINSICS
 #  endif
+#  if defined(__ADX__) && defined(BOOST_DECIMAL_HAS_MSVC_64BIT_INTRINSICS)
+#    define BOOST_DECIMAL_ADD_CARRY _addcarryx_u64
+#  elif defined(BOOST_DECIMAL_HAS_MSVC_64BIT_INTRINSICS)
+#    define BOOST_DECIMAL_ADD_CARRY _addcarry_u64
+#  endif
 #elif defined(__x86_64__)
 #  ifndef BOOST_DECIMAL_BUILD_MODULE
 #    include <x86intrin.h>