Summary
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Add a new enum constant `RELEASE_19` to `javax.lang.model.SourceVersion` for the JDK 19 release and update the FooVisitor14 visitors to cover release 19 as well.

Problem
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The `SourceVersion` enum needs an enum constant for each release being modeled.

Solution
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Append the enum constant `RELEASE_19` and update the visitor text and supported source version annotations to cover from RELEASE_14 to RELEASE_19.

Specification
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