Some native functions require a special helper method called a trampoline to make them easier to call from C#. This transformation applies the specified MethodImplOptions to all functions in the entire library. Typically it is used to enable aggressive inlining.
This transformation is entirely optional. Marking all functions with MethodImplOptions.AggressiveInlining may improve performance in libraries which require frequent use of functions via trampolines. (For example, all virtual methods require trampolines to perform the virtual method dispatch.)