Switch to oxidized flow parser (#19398)

Co-authored-by: fisker <lionkay@gmail.com>

changelog_unreleased/flow/19398.md

@@ -0,0 +1,15 @@
+#### Preserve Flow comment syntax and improve parser performance (#19398 by @SamChou19815)
+
+Prettier now uses Flow's Rust-backed parser. This preserves Flow comment syntax annotations instead of printing them as regular Flow syntax. In local parser-only benchmarks, `flow-parser/oxidized` parsed Prettier's valid Flow fixtures in 266.4ms median time, compared with 422.6ms for the old parser, and parsed `flow_parser.js` in 1298.0ms, compared with 2269.6ms.
+
+<!-- prettier-ignore -->
+```flow
+// Input
+function foo<T>(bar /*: T[] */, baz /*: T */) /*: S */ {}
+
+// Prettier stable
+function foo<T>(bar: T[], baz: T): S {}
+
+// Prettier main
+function foo<T>(bar /*: T[] */, baz /*: T */) /*: S */ {}
+```