Add CHANGELOG entry for banning OpReturn/OpReturnValue in inline asm!.

Author: eddyb

CHANGELOG.md

@@ -27,6 +27,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 -->
 
+## [Unreleased]
+
+### Fixed 🩹
+- [PR#1006](https://github.com/EmbarkStudios/rust-gpu/pull/1006) fixed [#1002](https://github.com/EmbarkStudios/rust-gpu/issues/1002) by rewriting away all `spirv-std` uses of `asm!("OpReturnValue %result")` and disallowing `OpReturn`/`OpReturnValue` from inline `asm!` (as it's always UB to leave `asm!` blocks in any way other than falling through their end)
+
 ## [0.6.0]
 
 ### Added ⭐