Util.GetArray causes several runtime errors

[hozuki]

The function Core.Util.GetArray uses a static array to lower array allocation costs, but newer version of SlimDX (currently I'm using SlimDX 4.0.13.44) seems to expect a array of exact length needed. For example, in LightingDemo, running this demo will throw a NullReferenceException, located at this line:

_fxPointLight.SetRawValue(new DataStream(array, false, false), array.Length);

With the help of the debugger I found that all fields of _fxPointLight became invalid. A watch on _fxPointLight shows that the change happens just after the _fxDirLight.SetRawValue call. So I canceled the static buffer and tried to create a new array of len bytes each time, and this modification worked. I suspect SlimDX neither fully checks the parameters nor handles this situation well and internal states of D3D just crash. This problem also affects other several demos.