Why the very first design time build after switching from console to VS IDE changes the *.csproj.AssemblyReference.cache files?

## Visual Studio Version
17.1.3

## Summary
I check the *.csproj.AssemblyReference.cache files after console msbuild and after the first design time build in VS IDE. They are different even though nothing has changed. Note that consecutive msbuild runs or regular builds in VS IDE do not change them. Only after switching from the console build to a new VS IDE instance that runs the first design time build do we see the issue.

## Steps to Reproduce

1. git clean -qdfx
2. build with msbuild
3. Save the *.csproj.AssemblyReference.cache files
4. build with msbuild
5. Save the *.csproj.AssemblyReference.cache files
6. open devenv
7. wait for the design time build to finish
8. Check the *.csproj.AssemblyReference.cache files

I have the binary logs and the selected files saved aside for each build including the design time build, but I do not want to upload them to a public location. Is there a private upload link?

## Expected Behavior
All the files are identical.

## Actual Behavior
The design time build produces a different file

## User Impact
I do not know. It may be a symptom of a bigger problem.