Internal modifier added to partial classes breaks new project creation for WinForms, WebTools and anything using partial classes in their templates #55703
Description
17.0.0 Preview 4.0 [31611.372.main]
Steps to Reproduce:
In latest internal VS builds, create a new WinForms C# project. Core, .NET 5+ or .NET Framework
Build the project
Expected Behavior:
Builds and runs as expected
Actual Behavior:
Additional Notes
The work done in #51935 and #55463 are likely culprits.
This is critically blocking dogfooding for several teams.
Can we get an update on timelines when we can expect fixes?
/cc: @Youssef1313 , @sharwell, @davidwengier , @jinujoseph , @Pilchie