iOS ContentLoad Error due to stripped MG assembly

[Krusheen]

This is very similar to issues on Android, the linker is trimming out assemblies it needs:

Android Release build can't find ContentTypeReader

The trimmer is removing mscorlib because it is used via reflection. Solution: https://community.monogame.net/t/trimming-linker-breaks-spritefont-loading/18296/2?u=thekelsam