Add Identifiable conformance to _IdentifiableNever

Author: li3zhen1

Sources/Grape/Contents/_IdentifiableNever.swift

@@ -3,11 +3,21 @@ public enum _IdentifiableNever<ID: Hashable> { }
 extension _IdentifiableNever: GraphContent {
     public typealias NodeID = ID
 
+    @inlinable
     public var body: Self {
         fatalError()
     }
 
+    @inlinable
     public func _attachToGraphRenderingContext(_ context: inout _GraphRenderingContext<NodeID>) {
         fatalError()
     }
+}
+
+
+extension _IdentifiableNever: Identifiable {
+    @inlinable
+    public var id: ID {
+        fatalError()
+    }
 }