Add missing code for parser entry template and fix build-script.py

[kimdv]

In #1346 code was modified on the file and not in the template

[kimdv]

@swift-ci please test

[kimdv]

The error was properly introduced in #1149 where we refactored the code-gen into a single executable.

Not sure why the CI didn't catch that before

[kimdv]

@swift-ci please test

[keith]

@kimdv looks like things don't build without this, is it good to merge?

[kimdv]

@kimdv looks like things don't build without this, is it good to merge?

For me yea. But we need approval from @ahoppen I think 🤔

[keith]

@swift-ci please test and merge

[keith]

Let's merge and do post-commit review if needed to unblock folks

[gottesmm]

@keith this broke the build: https://ci.swift.org/job/oss-swift-incremental-RA-macos/2331/. I am going to try reverting it.

[keith]

dang, sorry, thanks! looks like we need to run the integration tests before merging again

[ahoppen]

Not sure why the CI didn't catch that before

We don’t verify that the CodeGenerated files match the templates because running code generation requires us to check out an older version of SwiftSyntax (the one specified in the Package.swift of CodeGeneration). But CI doesn’t have internet access at that point to perform that checkout… So it’s a little tricky to do.