dnlib 4.0.0 issues

[greenozon]

When trying to use fresh dnlib version 4.0.0 Slayer shows never ending exceptions (when working inside VS), eg:

Exception thrown: 'System.NullReferenceException' in dnlib.dll
Object reference not set to an instance of an object.

Exception thrown: 'System.NullReferenceException' in dnlib.dll
Object reference not set to an instance of an object.

Exception thrown: 'System.NullReferenceException' in dnlib.dll
Object reference not set to an instance of an object.

.....

from within VS:

this issue refs to pending PR #73