Why this is needed:
- The dev wrapper persisted the selected version in .kotlinc_version, but only installed binaries when the selected version changed.
- After a clean working directory (which can remove .kotlinc_installed), the version file can still point at an already-selected compiler, causing forward execution to fail because the binary directory no longer exists.
What this changes:
- Make install() idempotent by returning early when install dir already exists.
- Call install() unconditionally from main() so the selected version is always materialised before forwarding.
- Keep explicit reinstall behaviour on version switches by removing the old install directory when selection changes.
This is an independent reliability fix and not tied to Kotlin 1.x test routing.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Add the Kotlin 2.4.0 compiler plugin variant (component registrar,
IR compatibility shims, and version-specific utilities), bundle the
2.4.0 compiler dependencies, and update the build wiring, supported
version metadata and the too-new diagnostic bound.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Also removed the version check step, as a version not existing will give
a 404 any way later on, and that was adding a delay.
The cache is stored in a `.kotlinc_zips` and will be cleaned up by
`--clear`.
