[Macros] Only operator-fold attribute syntax for attached macro

This change restores the previous behavior changed by a8472a9.
When expanding attached macros, macro implementation should only see the
macro attribute syntax is operator folded, other syntax nodes - node,
parentDeclNode, extendedType, and conformanceList - should not be
operator-folded.

rdar://162208759

Author: rintaro

Sources/SwiftCompilerPluginMessageHandling/Macros.swift

@@ -149,24 +149,26 @@ extension PluginProviderMessageHandler {
     let swiftVersion = staticBuildConfiguration?.parserSwiftVersion
     let experimentalFeatures = staticBuildConfiguration?.experimentalFeatures
 
-    func addToSourceManager(_ syntax: PluginMessage.Syntax) -> Syntax {
+    func addToSourceManager(_ syntax: PluginMessage.Syntax, foldOperators: Bool) -> Syntax {
       sourceManager.add(
         syntax,
         swiftVersion: swiftVersion,
         experimentalFeatures: experimentalFeatures,
-        foldingWith: .standardOperators
+        foldingWith: foldOperators ? .standardOperators : nil
       )
     }
 
-    let attributeNode = addToSourceManager(attributeSyntax)
+    let attributeNode = addToSourceManager(attributeSyntax, foldOperators: true)
       .cast(AttributeSyntax.self)
-    let declarationNode = addToSourceManager(declSyntax)
-    let parentDeclNode = parentDeclSyntax.map { addToSourceManager($0).cast(DeclSyntax.self) }
+    let declarationNode = addToSourceManager(declSyntax, foldOperators: false)
+    let parentDeclNode = parentDeclSyntax.map {
+      addToSourceManager($0, foldOperators: false).cast(DeclSyntax.self)
+    }
     let extendedType = extendedTypeSyntax.map {
-      addToSourceManager($0).cast(TypeSyntax.self)
+      addToSourceManager($0, foldOperators: false).cast(TypeSyntax.self)
     }
     let conformanceList = conformanceListSyntax.map {
-      let placeholderStruct = addToSourceManager($0).cast(StructDeclSyntax.self)
+      let placeholderStruct = addToSourceManager($0, foldOperators: false).cast(StructDeclSyntax.self)
       return placeholderStruct.inheritanceClause!.inheritedTypes
     }