RFR: 8329718: Incorrect `@since` tags in elements in jdk.compiler and java.compiler

[Nizar Benalla]

This PR aims to add `@since` tags in elements in both `jdk.compiler` and `java.compiler`.
A lot of these changes have to do with handling of preview features.

The existing rules for handling of `@since` for preview elements:
- When an element is still marked as preview, the `@since` should be the first JDK release where the element was added.
- If the element is no longer marked as preview, the `@since` should be the first JDK release where it was no longer preview.

It is tricky to check these, the way preview elements were annotated before the inroduction of `@Previewfeature` in JDK 17:
- in jdk 12-13 they were annotated with `@Deprecated(forRemoval=true, since=...)`
- in jdk 14-15 they were annotated with `@jdk.internal.preview` or with `{@preview Associated with ....` in the `javadoc` comment

If you're reviewing these changes, Thanks!

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Commit messages:
 - add `@since` tags to `java.compiler`
 - add `@since` tags to `jdk.compiler`

Changes: https://git.openjdk.org/jdk/pull/18972/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18972&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8329718
  Stats: 36 lines in 13 files changed: 25 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/18972.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18972/head:pull/18972

PR: https://git.openjdk.org/jdk/pull/18972