shield lifetime-dependence syntax

Author: glessard

Package.swift

@@ -145,6 +145,7 @@ let package = Package(
               .when(platforms: [.macOS, .iOS, .watchOS, .tvOS, .linux])
             ),
             .enableExperimentalFeature("AddressableTypes"),
+            .enableExperimentalFeature("AllowUnsafeAttribute"),
             .enableExperimentalFeature("BuiltinModule"),
             .enableExperimentalFeature("AccessLevelOnImport")
           ] + availabilityMacros + featureSettings,

Sources/FoundationEssentials/Data/Data.swift

@@ -2203,6 +2203,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
         return try _representation.withUnsafeBytes(body)
     }
 
+#if compiler(>=6.2) && $LifetimeDependence
     @available(FoundationSpan 6.2, *)
     public var bytes: RawSpan {
         @lifetime(borrow self)
@@ -2238,6 +2239,7 @@ public struct Data : Equatable, Hashable, RandomAccessCollection, MutableCollect
             return _overrideLifetime(span, borrowing: self)
         }
     }
+#endif
 
 #if compiler(>=5.9) && $InoutLifetimeDependence && $LifetimeDependenceMutableAccessors
     @available(FoundationSpan 6.2, *)
@@ -2974,7 +2976,7 @@ extension Data : Codable {
 }
 
 // TODO: remove once _overrideLifetime is public in the standard library
-
+#if compiler(>=6.2) && $LifetimeDependence
 /// Unsafely discard any lifetime dependency on the `dependent` argument. Return
 /// a value identical to `dependent` with a lifetime dependency on the caller's
 /// borrow scope of the `source` argument.
@@ -3006,6 +3008,7 @@ internal func _overrideLifetime<
 ) -> T {
   dependent
 }
+#endif
 
 #if compiler(>=5.9) && $InoutLifetimeDependence && $LifetimeDependenceMutableAccessors
 /// Unsafely discard any lifetime dependency on the `dependent` argument.