* Convert it into a MM8027/MT8027 error (with documentation).
* Add information about the selector and managed method that triggered the error.
Now the problem reported in issue #4254 shows up as:
> ObjCRuntime.RuntimeException: Failed to marshal the Objective-C object 0x7f8080412810 (type: UIView). Could not find an existing managed instance for this object, nor was it possible to create a new managed instance (because the type 'UIKit.UIView&' does not have a constructor that takes one IntPtr argument).
> Additional information:
> Selector: popoverController:willRepositionPopoverToRect:inView:
> Method: UIKit.UIPopoverController+_UIPopoverControllerDelegate.WillReposition(UIKit.UIPopoverController, CoreGraphics.CGRect ByRef, UIKit.UIView ByRef)
instead of just:
> ObjCRuntime.RuntimeException: Failed to marshal the Objective-C object 0x7f8080412810 (type: UIView). Could not find an existing managed instance for this object, nor was it possible to create a new managed instance (because the type 'UIKit.UIView&' does not have a constructor that takes one IntPtr argument).
which makes it much easier to understand, track down, and fix/work around,
both for customers and ourselves.