Handle ReflectionTypeLoadException in jnimarshalmethod-gen.exe

[radekdoulik]

After XA mono bump to mono-2018-06 I am seeing jnimarshalmethod-gen.exe crashes with unhandled exception like the one below. It happens when building the XF test in XA.

EXEC : error : jnimarshalmethod-gen: Unable to process assembly 'obj/Release/linksrc/Xamarin.Forms.Performance.Integration.Droid.dll' [/Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/tests/Xamarin.Forms-Performance-Integration/Droid/Xamarin.Forms.Performance.Integration.Droid.csproj]
  Exception of type 'System.Reflection.ReflectionTypeLoadException' was thrown. (TaskId:3132)
  System.Reflection.ReflectionTypeLoadException: Exception of type 'System.Reflection.ReflectionTypeLoadException' was thrown. (TaskId:3132)
    at (wrapper managed-to-native) System.Reflection.Assembly.GetTypes(System.Reflection.Assembly,bool) (TaskId:3132)
    at System.Reflection.Assembly.GetTypes () [0x00000] in /Users/builder/jenkins/workspace/xamarin-android/xamarin-android/external/mono/mcs/class/corlib/System.Reflection/Assembly.cs:410  (TaskId:3132)
    at System.Reflection.Assembly+<get_DefinedTypes>d__141.MoveNext () [0x0001e] in /Users/builder/jenkins/workspace/xamarin-android/xamarin-android/external/mono/mcs/class/corlib/System.Reflection/Assembly.cs:1025  (TaskId:3132)
    at Xamarin.Android.Tools.JniMarshalMethodGenerator.App.CreateMarshalMethodAssembly (System.String path) [0x0034f] in /Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/external/Java.Interop/tools/jnimarshalmethod-gen/App.cs:248  (TaskId:3132)
    at Xamarin.Android.Tools.JniMarshalMethodGenerator.App.ProcessAssemblies (System.Collections.Generic.List`1[T] assemblies) [0x0010a] in /Users/builder/jenkins/workspace/xamarin-android-pr-builder/xamarin-android/external/Java.Interop/tools/jnimarshalmethod-gen/App.cs:179  (TaskId:3132)