fix(lsp): don't overlay insertion-style inline completions (#36477)

* feat(lua): `Range:is_empty()` to check vim.range emptiness

* fix(lsp): don't overlay insertion-style inline completions

**Problem:** Some servers commonly respond with an empty inline
completion range which acts as a position where text should be inserted.
However, the inline completion module assumes that all responses with a
range are deletions + insertions that thus require an `overlay` display
style. This causes an incorrect preview, because the virtual text should
have the `inline` display style (to reflect that this is purely an
insertion).

**Solution:** Only use `overlay` for non-empty replacement ranges.

0 files changed, 0 insertions, 0 deletions