To reproduce:
1. Open users attached project "UnityTest.zip"
2. Build for iOS
3. Open the built project with Xcode and deploy it to an iOS device
4. In Xcode, when the app is launched press "Show The Debug Navigator" button in the top left corner
5. Select memory tab and observe the graphs

Expected result: memory usage is consistent
Actual result: memory usage increases over time until the app crashes

Reproduced on:
2017.3.2f1 2017.4.6f1 2018.1.7f1 2018.2.0a4

Not reproduced on:
2018.2.0a5 2018.2.0b1 2018.2.0b11 2018.3.0a3

Reproduced on:
iPhone 7 iOS 11.0 A10

NOTES:

This is not mobile related.

Also reproduces on:
Google Pixel 2, OS: 8.1.0, CPU: arm64-v8a, GPU: Adreno (TM) 540
iMac macOS 10.13.5
Windows 10 machine