Trivially removing some unused left-over `LambdaForm$Kind` enums. - Last use of `COLLECT` and `SPREAD` was removed by fac39fe9 - `FIELD` was added by 8d5f5b9a but had no usage from the start - Last use of `CONVERT` was removed by eda5f090
------------- Commit messages: - 8341776: Remove unused enum values from LambdaForm Changes: https://git.openjdk.org/jdk/pull/21592/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=21592&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8341776 Stats: 4 lines in 1 file changed: 0 ins; 4 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/21592.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/21592/head:pull/21592 PR: https://git.openjdk.org/jdk/pull/21592
