`AllowShortRecordOnASingleLine` (introduced for C++ records) made
`LineJoiner::tryFitMultipleLinesInOne` route Java `TT_RecordLBrace`
lines to `tryMergeRecord`, which only handles C++ class/struct/union
records. Empty Java `interface` and `record` bodies were therefore no
longer merged onto a single line, regressing the behavior that
`BraceWrapping.SplitEmptyRecord: false` previously provided.
Handle Java records separately and restore the pre-existing
`SplitEmptyRecord`-based merge.
Fixes#219711
(cherry picked from commit 6d390ea43be046d62bc880524ffc4734a21307a7)
Cyrus Ding
13259bad3b