Steps to reproduce:
1. Download 1042218_repro.zip
2. Switch platform to UWP
3. In Project Settings set Scripting backend too .NET
4. Build project
5. Open solution in VS
6. Build project (Debug, x64, run on Local Machine)
6. Check Process memory in the Diagnostic Tools window

Expected results: memory usage doesn't increase over time.
Actual results: memory usage increase over time when UWP project is built with .NET backend.
Memory leak is caused by Mesh.SetVertices(), Mesh.SetUVs(), Mesh.SetTriangles().

Reproduced with: 2018.2.0b6, 2018.1.2f1, 2017.4.4f1, 2017.3.2f1, 2017.2.3p1, 2017.1.4f1

Workaround: switch Scripting backend in Project Setting to IL2CPP.