IL2025: Duplicate preserve of a member in a descriptor file

Cause

A member on a type is marked for preservation more than once in a descriptor file.

Rule description

Descriptor files are used to instruct the trimmer to always keep certain items in an assembly, regardless of whether the trimmer could find any references to them.

Members in this file should only appear once.

Example

<!-- IL2025: Duplicate preserve of 'method' -->
<linker>
  <assembly fullname="MyAssembly">
    <type fullname="MyType">
      <method name="MyMethod"/>
      <method name="MyMethod"/>
    </type>
  </assembly>
</linker>