Add ChangeLog entry for SE-0322

Author: DougGregor

CHANGELOG.md

@@ -146,6 +146,13 @@ Swift 5.6
   }
   ```
 
+* [SE-0322][]:
+
+  The standard library now provides a new operation
+  `withUnsafeTemporaryAllocation` which provides an efficient temporarily
+  allocation within a limited scope, which will be optimized to use stack
+  allocation when possible.
+
 * [SE-0315][]:
 
   Type expressions and annotations can now include "type placeholders" which
@@ -8853,6 +8860,7 @@ Swift 1.0
 [SE-0313]: <https://github.com/apple/swift-evolution/blob/main/proposals/0313-actor-isolation-control.md>
 [SE-0315]: <https://github.com/apple/swift-evolution/blob/main/proposals/0315-placeholder-types.md>
 [SE-0316]: <https://github.com/apple/swift-evolution/blob/main/proposals/0316-global-actors.md>
+[SE-0322]: <https://github.com/apple/swift-evolution/blob/main/proposals/0322-temporary-buffers.md>
 [SE-0324]: <https://github.com/apple/swift-evolution/blob/main/proposals/0324-c-lang-pointer-arg-conversion.md>
 [SE-0323]: <https://github.com/apple/swift-evolution/blob/main/proposals/0323-async-main-semantics.md>
 [SE-0328]: <https://github.com/apple/swift-evolution/blob/main/proposals/0328-structural-opaque-result-types.md>