Rust

add fast-path for `with_new_children` #36

Job	Run time
Verify Vendored Code	1m 23s
build and run with wasm-pack	4m 57s
Verify MSRV (Min Supported Rust Version)	4m 59s
Check cargo fmt	1m 13s
cargo test (macos-aarch64)	5m 52s
linux build test	3m 2s
cargo check datafusion-common features	0s
cargo test doc (amd64)	0s
cargo test datafusion-cli (amd64)	0s
cargo check datafusion-functions features	0s
check Cargo.toml formatting	0s
cargo check datafusion-substrait features	0s
cargo examples (amd64)	0s
verify benchmark results (amd64)	0s
cargo check datafusion-proto features	0s
check example README is up-to-date	0s
cargo doc	0s
cargo test (amd64)	0s
Run sqllogictest in Substrait round-trip mode	0s
clippy	0s
check configs.md and ***_functions.md is up-to-date	0s
cargo check datafusion features	0s
Run sqllogictest with Postgres runner	0s
	21m 26s

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