Make our use of SwiftSyntax APIs more resilient to precompiled SwiftSyntax

Author: mbrandonw

Package.resolved

@@ -86,6 +86,8 @@ extension AttributeListSyntax.Element {
       if let availability = ifConfig.availability {
         return .ifConfigDecl(availability)
       }
+    @unknown default:
+      return nil
     }
     return nil
   }

Sources/ComposableArchitectureMacros/Availability.swift

@@ -215,13 +215,11 @@ extension VariableDeclSyntax {
 }
 
 extension ObservableStateMacro: MemberMacro {
-  public static func expansion<
-    Declaration: DeclGroupSyntax,
-    Context: MacroExpansionContext
-  >(
+  public static func expansion(
     of node: AttributeSyntax,
-    providingMembersOf declaration: Declaration,
-    in context: Context
+    providingMembersOf declaration: some DeclGroupSyntax,
+    conformingTo protocols: [TypeSyntax],
+    in context: some MacroExpansionContext
   ) throws -> [DeclSyntax] {
     guard !declaration.isEnum
     else {

Sources/ComposableArchitectureMacros/ObservableStateMacro.swift

@@ -219,7 +219,7 @@ extension TypeSyntax {
       genericArgumentClause: GenericArgumentClauseSyntax(
         arguments: [
           GenericArgumentSyntax(
-            argument: self
+            argument: GenericArgumentSyntax.Argument(self)
           )
         ]
       )