runtime: System.IntPtr(long) constructor throws overflow

The current .NET Framework on Windows and CoreCLR have the following implementation for System.IntPtr(long):

public unsafe IntPtr(long value)
{
    #if WIN32
        m_value = (void *)checked((int)value);
    #else
        m_value = (void *)value;
    #endif
}

This is quite unfortunate on 32-bit platforms because if you get a pointer value as a long which has the higher bit set, it will always throw an overflow exception.

To reproduce:

IntPtr ptr = new IntPtr(0x80000000);

The code should have been:

public unsafe IntPtr(long value)
{
    #if WIN32
        m_value = (void *)checked((uint)value);
    #else
        m_value = (void *)value;
    #endif
}

since we only care that the higher 32-bits of the long parameter are all zeros.