* Update dependencies from https://github.com/mono/linker build 20210415.1

Microsoft.NET.ILLink.Tasks
 From Version 6.0.100-preview.2.21212.5 -> To Version 6.0.100-preview.2.21215.1

* Update dependencies from https://github.com/mono/linker build 20210415.2

Microsoft.NET.ILLink.Tasks
 From Version 6.0.100-preview.2.21212.5 -> To Version 6.0.100-preview.2.21215.2
Co-authored-by: Ndotnet-maestro[bot] <dotnet-maestro[bot]@users.noreply.github.com>
Co-authored-by: NAlexander Köplinger <alex.koeplinger@outlook.com>