To reproduce:
1. Open project attached by the user
2. Build project for Android with "Main" scene attached in build settings
3. Notice that build failed and errors appeared in the console

Expected: Unity should successfully build project
Actual: Build fails with following error:
il2cpp.exe didn't catch exception: Unity.IL2CPP.Building.BuilderFailedException: /Users/vaidas/Downloads/case_960211-Net46TestUnity/Temp/StagingArea/Il2Cpp/il2cppOutput/GenericMethods2.cpp:25914:10: error: cannot initialize return object of type 'RuntimeObject **' (aka 'Il2CppObject *') with an lvalue of type 'int32_t ' (aka 'int *')
return L_1;

Reproduced with: 2017.1.2p1, 2017.2.0f3, 2017.3.0b4, 2018.1.0a1
Wasn't able to reproduce on iOS platform, build succeeds without any errors.

WON'T FIX:
Unfortunately, the AsRef method that is not compiling correctly uses ref returns, which are a C# 7 feature. Unity doesn't support C# 7 in 2017.2. We're working on adding support for it in a newer version of Unity, but it is not ready yet. So for the time being, this is not a bug we can correct. Look for C# 7 support coming later though, when this should work.