Add call to report_errors() to limits_test.cpp.

test/limits_test.cpp

@@ -207,7 +207,7 @@ int cpp_main(int, char*[])
   test_float_limits(long_double(), "long double");
   // Some compilers don't pay attention to std:3.6.1/5 and issue a
   // warning here if "return 0;" is omitted.
-  return 0;
+  return boost::report_errors();
 }