Regression in build incrementalism for Blazor

[captainsafia]

Moving this issue over from email thread.

Describe the bug

Changes made to a Blazor project are not reflected when running the project using:

$ dotnet build
$ dotnet run

To Reproduce

1. Create a new Blazor WASM project.

$ dotnet new blazorwasm -o repro

2. Build and run the project using either VS or the CLI.

$ dotnet build
$ dotnet run

3. Make a modification to the project sources. For example, add a Console.WriteLine statement.

4. Build and run the project.

5. Observe that your source change in replace batch files with kvm #3 "doesn't work".

Further technical details

This was reproduced on preview4 bits for Blazor WASM.

[javiercn]

Looking into it.