Precompilation + TagHelpers in different project do not recompile changed TagHelpers.

[NTaylorMullen]

If you have TagHelpers in another project and you're @addTagHelpering them into your own, if using precompilation changes are not reflected in the runtime code.

Repro:
TagHelper in another project:

public class FooTagHelper : TagHelper
{
    public string Bar { get; set; }
}

<foo bar="true" />

Change FooTagHelper's Bar property to be a bool. Razor page doesn't pick up on the modified TagHelper even when closing/reopening file. An error occurs. In the case that the tooling is smart enough to not show the error and let you build, runtime fails.

[pranavkm]

Addressed as part of 2e32ffc