Try to suppress some more Visual C++ warnings.

[SVN r57976]

test/hash_complex_test.cpp

@@ -25,6 +25,9 @@ int main() {}
 #pragma warning(disable:4305) // truncation from 'double' to 'const std::complex<float>::_Ty'
 #pragma warning(disable:4309) // truncation of constant value
 #pragma warning(disable:4512) // assignment operator could not be generated
+#if BOOST_MSVC < 1400
+#pragma warning(disable:4267) // conversion from 'size_t' to 'unsigned int', possible loss of data
+#endif
 #endif
 
 #include <complex>