Rust

add fast-path for `with_new_children` #53

Job	Run time
build and run with wasm-pack	5m 6s
Verify MSRV (Min Supported Rust Version)	4m 50s
Check cargo fmt	1m 18s
linux build test	4m 2s
cargo test (macos-aarch64)	17m 10s
Verify Vendored Code	1m 18s
cargo check datafusion-substrait features	10m 36s
cargo check datafusion-common features	1m 52s
cargo check datafusion-proto features	4m 36s
cargo check datafusion features	11m 12s
cargo test (amd64)	9m 50s
cargo examples (amd64)	9m 15s
Run sqllogictest with Postgres runner	6m 15s
Run sqllogictest in Substrait round-trip mode	6m 13s
cargo check datafusion-functions features	2m 22s
check configs.md and ***_functions.md is up-to-date	4m 56s
cargo doc	4m 55s
check example README is up-to-date	36s
verify benchmark results (amd64)	10m 44s
cargo test datafusion-cli (amd64)	4m 13s
cargo test doc (amd64)	7m 49s
check Cargo.toml formatting	3m 21s
clippy	4m 19s
	2h 16m 48s

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