Fix compilation for iOS

Author: pcuenca

Diffusion/ModelInfo.swift

@@ -41,8 +41,12 @@ struct ModelInfo {
 extension ModelInfo {
     static var defaultAttention: AttentionVariant {
         guard runningOnMac else { return .splitEinsum }
+        #if os(macOS)
         guard Capabilities.hasANE else { return .original }
         return Capabilities.performanceCores >= 8 ? .original : .splitEinsum
+        #else
+        return .splitEinsum
+        #endif
     }
 
     var bestAttention: AttentionVariant {

Diffusion/Views/TextToImage.swift

@@ -88,6 +88,8 @@ struct ImageWithPlaceholder: View {
             })
         case .failed(_):
             return AnyView(Image(systemName: "exclamationmark.triangle").resizable())
+        case .userCanceled:
+            return AnyView(Text("Generation canceled"))
         }
     }
 }