[fpc-pascal] Problem with c header conversion

[dmitry boyarintsev]

each "union" is a separate case for pascal. another thing is that the
structure is quite agly and does not reveale the logicals usage.
The problem is that pascal does not allow you to use multiple cases in
single record, that would require you to declare additional types.

  _PFColorSize = record
  case Integer of
    0: (dwRGBBitCount : DWORD);
    1: (dwYUVBitCount : DWORD);
    2: (dwAlphaBitDepth : DWORD);
  end;

  _PFColorMask = record
  case Integer of
    0: (
       dwRBitMask : DWORD;
       dwGBitMask : DWORD;
       dwBBitMask : DWORD;
       dwRGBAAlphaBitMask: DWORD;
       );
    1: (dwYBitMask : DWORD;
        dwUBitMask : DWORD;
        dwVBitMask : DWORD
    );
  end;

  PDDPixelFormat = ^TDDPixelFormat;
 _DDPIXELFORMAT = record
   dwSize: DWORD;
   dwFlags: DWORD;
   dwFourCC: DWORD;
   _size : PFColorSize;
   _mask : PFColorMask;
 end;
 DDPIXELFORMAT = _DDPIXELFORMAT;
 TDDPixelFormat = _DDPIXELFORMAT;