[jdk23u] RFR: 8337998: CompletionFailure in getEnclosingType attaching type annotations [v2]

[Liam Miller-Cushon]

> This change fixes a javac crash when classes are missing from the classpath. The fix causes javac to instead report a non-crash error diagnostic. The change improves logic first added in JDK 22 as part of the fix for JDK-8225377.

Liam Miller-Cushon has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'master' into JDK-8337998
 - Backport 9e282e5c966a9c065de8b901b7d30bb5c9ccf243

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Changes:
  - all: https://git.openjdk.org/jdk23u/pull/68/files
  - new: https://git.openjdk.org/jdk23u/pull/68/files/bc7e1b47..3d938a6d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk23u&pr=68&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk23u&pr=68&range=00-01

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk23u/pull/68.diff
  Fetch: git fetch https://git.openjdk.org/jdk23u.git pull/68/head:pull/68

PR: https://git.openjdk.org/jdk23u/pull/68