Merge pull request #73096 from meg-gupta/unsafeattr

Allow `@_unsafeNonescapableResult` on accessors

Author: meg-gupta

include/swift/AST/DeclAttr.def

@@ -372,7 +372,7 @@ SIMPLE_DECL_ATTR(_nonescapable, NonEscapable,
   OnNominalType | UserInaccessible | ABIBreakingToAdd | ABIStableToRemove | APIBreakingToAdd | APIStableToRemove,
   148)
 SIMPLE_DECL_ATTR(_unsafeNonescapableResult, UnsafeNonEscapableResult,
-  OnAbstractFunction | OnSubscript | UserInaccessible | ABIStableToAdd | ABIStableToRemove | APIBreakingToAdd | APIBreakingToRemove,
+  OnAbstractFunction | OnSubscript | OnAccessor | UserInaccessible | ABIStableToAdd | ABIStableToRemove | APIBreakingToAdd | APIBreakingToRemove,
   149)
 CONTEXTUAL_SIMPLE_DECL_ATTR(final, Final,
   OnClass | OnFunc | OnAccessor | OnVar | OnSubscript | DeclModifier | ABIBreakingToAdd | ABIBreakingToRemove | APIStableToAdd | APIStableToRemove,

test/attr/attr_nonEscapable.swift

@@ -1,8 +1,8 @@
-// RUN: %target-typecheck-verify-swift -enable-experimental-feature NonescapableTypes
+// RUN: %target-typecheck-verify-swift -enable-experimental-feature NonescapableTypes -enable-experimental-feature NoncopyableGenerics
 
 // REQUIRES: asserts
 
-@_nonescapable public struct NES {
+public struct NES : ~Escapable {
   let x: Int
 
   @_unsafeNonescapableResult
@@ -15,3 +15,12 @@
     return NES()
   }
 }
+
+struct BC {
+  public var nes: NES {
+    @_unsafeNonescapableResult
+    get {
+      NES()
+    }
+  }
+}