https://github.com/denoland/deno_install
1. This allows the installer to use a more aggressive CI build matrix
with different version of python.
2. Running the installer during tools/test.py artificially inflates our
download stats.
3. Running the installer during tools/test.py makes the test script
dependent on having an internet connection.
4. Running the installer during tools/test.py introduces a race
condition during release - where it tries and fails to download the
latest release in build process that should be uploading that release.
- Add build scripts for Rust flatbuffers.
- Rewrites some reply.cc methods in Rust.
- Changes some struct elements to table in msg.fbs (rust flatbuffers
lacks support currently)
- Renames handlers_test to test_rs.
- This reorg is needed to make progress on the code cache handler.
