Add changelog entries

Author: andyleiserson

CHANGELOG.md

@@ -67,8 +67,11 @@ Bottom level categories:
 
 #### Naga
 
-Naga now infers the correct binding layout when a resource appears only in an assignment to `_`. By @andyleiserson in [#7540](https://github.com/gfx-rs/wgpu/pull/7540).
-
+- Compaction changes by @andyleiserson in [#7703](https://github.com/gfx-rs/wgpu/pull/7703):
+  - Naga's [`process_overrides`](https://docs.rs/naga/latest/naga/back/pipeline_constants/fn.process_overrides.html) function now compacts the module to remove unused items. It is no longer necessary to supply values for overrides that are not used by the active entry point.
+  - The `compact` Cargo feature has been removed. It is no longer possible to exclude compaction support from the build.
+  - The [`compact`](https://docs.rs/naga/latest/naga/compact/fn.compact.html) function has an additional argument that specifies whether to remove unused functions, globals, and named types and overrides. For the previous behavior, pass `KeepUnused::Yes`.
+- Naga now infers the correct binding layout when a resource appears only in an assignment to `_`. By @andyleiserson in [#7540](https://github.com/gfx-rs/wgpu/pull/7540).
 - Implement `dot4U8Packed` and `dot4I8Packed` for all backends, using specialized intrinsics on SPIR-V, HSLS, and Metal if available, and polyfills everywhere else. By @robamler in [#7494](https://github.com/gfx-rs/wgpu/pull/7494), [#7574](https://github.com/gfx-rs/wgpu/pull/7574), and [#7653](https://github.com/gfx-rs/wgpu/pull/7653).
 - Add polyfilled `pack4x{I,U}8Clamped` built-ins to all backends and WGSL frontend. By @ErichDonGubler in [#7546](https://github.com/gfx-rs/wgpu/pull/7546).
 - Allow textureLoad's sample index arg to be unsigned. By @jimblandy in [#7625](https://github.com/gfx-rs/wgpu/pull/7625).