Add release notes for 3.0.0 (bytecodealliance#5213)

RELEASES.md

@@ -6,8 +6,71 @@ Unreleased.
 
 ### Added
 
+* New `WasiCtx::{push_file, push_dir}` methods exist for embedders to add their
+  own objects.
+  [#5027](https://github.com/bytecodealliance/wasmtime/pull/5027)
+
+* Wasmtime's `component-model` support now supports `async` host functions and
+  embedding in the same manner as core wasm.
+  [#5055](https://github.com/bytecodealliance/wasmtime/pull/5055)
+
+* The `wasmtime` CLI executable now supports a `--max-wasm-stack` flag.
+  [#5156](https://github.com/bytecodealliance/wasmtime/pull/5156)
+
+* AOT compilation support has been implemented for components (aka the
+  `component-model` feature of the Wasmtime crate).
+  [#5160](https://github.com/bytecodealliance/wasmtime/pull/5160)
+
+* A new `wasi_config_set_stdin_bytes` function is available in the C API to set
+  the stdin of a WASI-using module from an in-memory slice.
+  [#5179](https://github.com/bytecodealliance/wasmtime/pull/5179)
+
+* When using the pooling allocator there are now options to reset memory with
+  `memset` instead of `madvisev` on Linux to keep pages resident in memory to
+  reduce page faults when reusing linear memory slots.
+  [#5207](https://github.com/bytecodealliance/wasmtime/pull/5207)
+
 ### Changed
 
+* Consuming 0 fuel with 0 fuel left is now considered to succeed. Additionally a
+  store may not consume its last unit of fuel.
+  [#5013](https://github.com/bytecodealliance/wasmtime/pull/5013)
+
+* A number of variants in the `wasi_common::ErrorKind` enum have been removed.
+  [#5015](https://github.com/bytecodealliance/wasmtime/pull/5015)
+
+* Methods on `WasiDir` now error-by-default instead of requiring a definition by
+  default.
+  [#5019](https://github.com/bytecodealliance/wasmtime/pull/5019)
+
+* Bindings generated by the `wiggle` crate now always depend on the `wasmtime`
+  crate meaning crates like `wasi-common` no longer compile for platforms such
+  as `wasm32-unknown-emscripten`.
+  [#5137](https://github.com/bytecodealliance/wasmtime/pull/5137)
+
+* Error handling in the `wasmtime` crate's API has been changed to primarily
+  work with `anyhow::Error` for custom errors. The `Trap` type has been replaced
+  with a simple `enum Trap { ... }` and backtrace information is now stored as a
+  `WasmBacktrace` type inserted as context into an `anyhow::Error`.
+  Host-functions are expected to return `anyhow::Result<T>` instead of the prior
+  `Trap` error return from before. Additionally the old `Trap::i32_exit`
+  constructor is now a concrete `wasi_commont::I32Exit` type which can be tested
+  for with a `downcast_ref` on the error returned from Wasmtime.
+  [#5149](https://github.com/bytecodealliance/wasmtime/pull/5149)
+
+* Configuration of the pooling allocator is now done through a builder-style
+  `PoolingAllocationConfig` API instead of the prior enum-variant API.
+  [#5205](https://github.com/bytecodealliance/wasmtime/pull/5205)
+
+### Fixed
+
+* The instruction cache is now properly flushed for AArch64 on Windows.
+  [#4997](https://github.com/bytecodealliance/wasmtime/pull/4997)
+
+* Backtrace capturing with many sequences of wasm->host calls on the stack no
+  longer exhibit quadratic capturing behavior.
+  [#5049](https://github.com/bytecodealliance/wasmtime/pull/5049)
+
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 ## 2.0.1