Oxc parser beats SWC with arena allocation

This is the kind of performance story compiler engineers care about because it comes from data layout and allocation strategy, not marketing fluff.

• –Arena allocation cuts per-node allocation overhead, which is exactly where parsers lose time on large JavaScript and TypeScript inputs
• –Keeping AST nodes in contiguous memory improves cache locality, so traversal and later compiler passes benefit too
• –Oxc matters beyond isolated parser benchmarks because it already feeds a larger Rust toolchain that powers projects like Rolldown and parts of Nuxt
• –The comparison also shows how the Rust tooling race has shifted from language choice alone to low-level architecture decisions
• –Developers should still treat parser wins as one layer of total build speed, since transforms, bundling, plugins, and I/O can dominate real-world performance