Reject ambiguous Builder class name collisions

[snowykte0426]

Summary

• reject simple-name @Builder when builderClassName resolves to Builder, suggesting @lombok.Builder instead
• apply the same simple-name collision rule to @SuperBuilder / SuperBuilder
• add javac and ECJ transform fixtures for rejected simple annotations and allowed fully-qualified annotations

Fixes #3857.

Tests

• JAVA_HOME=$(/usr/libexec/java_home -v 21) ant -noinput test.javacCurrent
• git diff --check
• JAVA_HOME=$(/usr/libexec/java_home -v 21) ant -noinput dist test.eclipse-202503 confirms the new Builder/SuperBuilder cases pass; the target still fails later on existing ecj-ValUndenotable.java missing expected output.

[rspilker]

@snowykte0426 Thanks for this contribution as well. Can you add your name to the AUTHORS file, so we are legally covered?

In the meantime, we've promoted SuperBuilder out of experimental. Can you replace your references to lombok.experimental.SuperBuilder by lombok.SuperBuilder. experimental.SuperBuilder is not yet deprecated, but it will be in an upcoming release.

[snowykte0426]

Thanks, @rspilker! Added myself to AUTHORS.

I also rebased onto current master and replaced the remaining lombok.experimental.SuperBuilder references — the qualified name in the error message (javac + eclipse) and the test resources — with lombok.SuperBuilder. ant test passes.