Prepare wasmi 0.18.1 release (#511)

* write changelog for wasmi version 0.18.1

* bump wasmi version 0.18.0 -> 0.18.1

CHANGELOG.md

@@ -6,6 +6,30 @@ The format is loosely based on [Keep a Changelog](https://keepachangelog.com/en/
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 Additionally we have an `Internal` section for changes that are of interest to developers.
 
+## [0.18.1] - 2022-10-13
+
+### Changed
+
+- Optimize for common cases for branch and return instructions.
+  (https://github.com/paritytech/wasmi/pull/493)
+    - This led to up to 10% performance improvement according to our benchmarks
+      in some cases.
+- Removed extraneous `S: impl AsContext` generic parameter from `Func::typed` method.
+- Make `IntoFunc`, `WasmType` and `WasmRet` traits publicly available.
+- Add missing impl for `WasmRet` for `Result<T, Trap> where T: WasmType`.
+    - Without this impl it was impossible to provide closures to `Func::wrap`
+      that returned `Result<T, Trap>` where `T: WasmType`, only `Result<(), Trap>`
+      or `Result<(T,), Trap>` was possible before.
+
+### Internal
+
+- Added `wasmi_arena` crate which defines all internally used arena data structures.
+  (https://github.com/paritytech/wasmi/pull/502)
+- Update to `clap 4.0` in `wasmi_cli`. (https://github.com/paritytech/wasmi/pull/498)
+- Many more improvements to our internal benchmarking CI.
+  (https://github.com/paritytech/wasmi/pull/494, https://github.com/paritytech/wasmi/pull/501,
+  https://github.com/paritytech/wasmi/pull/506, https://github.com/paritytech/wasmi/pull/509)
+
 ## [0.18.0] - 2022-10-02
 
 ### Added

crates/wasmi/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "wasmi"
-version = "0.18.0"
+version = "0.18.1"
 documentation = "https://docs.rs/wasmi/"
 description = "WebAssembly interpreter"
 exclude = ["tests/*", "benches/*"]