Added safety check for StructLayout in CodeReorganizationAvailablityLogic

[magoocas]

Related to issue #239.

Required to prevent re-organization of structs or classes that are meant to be marshalled to a Native function (Order is important).

[StructLayout(LayoutKind.Sequential)]
public struct Example
{
    int var1;
    int var3; //needs to stay above var2
    int var2;
}

[codecadwallader]

Thank you for submitting a pull request. We actually already have logic in place to detect the StructLayout attribute and prevent reorganization from running. It happens a little deeper down the stack which allows for you to reorganize a file but a particular member (e.g. a private struct within a class) is the only member that is skipped.

https://github.com/codecadwallader/codemaid/blob/master/CodeMaid/Logic/Reorganizing/CodeReorganizationManager.cs#L221

Are you seeing a scenario where this logic isn't working?

[magoocas]

Huh, well I'll be. I did have a case (the reason I went looking in the source in the first place) but now I can't seem to replicate it.

Sorry about that, my bad.

That'll teach me for submitting a pull request when I have a cold!

[codecadwallader]

No worries. If you stumble back into a scenario feel free to holler or submit a new pull. :)