Rust

add fast-path for `with_new_children` #47

Job	Run time
linux build test	3m 48s
cargo test (macos-aarch64)	11m 47s
Verify Vendored Code	1m 25s
build and run with wasm-pack	5m 7s
Verify MSRV (Min Supported Rust Version)	5m 2s
Check cargo fmt	1m 17s
cargo check datafusion-proto features	4m 29s
cargo check datafusion-common features	2m 1s
cargo check datafusion-functions features	2m 41s
cargo check datafusion-substrait features	10m 5s
cargo check datafusion features	11m 4s
cargo test (amd64)	10m 46s
check example README is up-to-date	34s
Run sqllogictest in Substrait round-trip mode	6m 17s
check Cargo.toml formatting	3m 19s
check configs.md and ***_functions.md is up-to-date	5m 22s
cargo doc	4m 45s
clippy	4m 34s
verify benchmark results (amd64)	10m 24s
cargo test datafusion-cli (amd64)	4m 9s
cargo test doc (amd64)	7m 34s
Run sqllogictest with Postgres runner	6m 34s
cargo examples (amd64)	9m 7s
	2h 12m 11s

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