Version 1.2.1

Changes:

• Performance improvements.
• Rewrite of checking whether we're inside readonly member / init accessor / .ctor / .cctor logic.
• Support HAM0003 for applicable Nullable<T> members on older runtimes without readonly members in the BCL (as opposed to the previous HAM0001).
• Catch previously missed unnecessary defensive copy caused by calling a member defined on a base type of a readonly struct via a constrained call.

Full Changelog: v1.2.0...v1.2.1