[cfe] Add ScopeProvider as an interface of Field

Part of https://github.com/dart-lang/sdk/issues/61572

Change-Id: I8a9cb883181a584ceac9aef6a863e135474026eb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/495960
Reviewed-by: Johnni Winther <johnniwinther@google.com>
Commit-Queue: Chloe Stefantsova <cstefantsova@google.com>

pkg/kernel/lib/src/ast/members.dart

@@ -264,7 +264,7 @@ sealed class Member extends NamedNode implements Annotatable, FileUriNode {
 ///
 /// The implied getter and setter for the field are not represented explicitly,
 /// but can be made explicit if needed.
-class Field extends Member {
+class Field extends Member implements ScopeProvider {
   DartType type; // Not null. Defaults to DynamicType.
   int flags = 0;
   Expression? initializer; // May be null.
@@ -291,6 +291,9 @@ class Field extends Member {
   /// in the field values of [InstanceConstant].
   Reference get fieldReference => super.reference;
 
+  @override
+  Scope? scope;
+
   Field.mutable(
     Name name, {
     this.type = const DynamicType(),

pkg/kernel/lib/src/equivalence.dart

@@ -2342,6 +2342,9 @@ class EquivalenceStrategy {
     if (!checkField_setterReference(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
+    if (!checkField_scope(visitor, node, other)) {
+      result = visitor.resultOnInequivalence;
+    }
     if (!checkField_fileEndOffset(visitor, node, other)) {
       result = visitor.resultOnInequivalence;
     }
@@ -8030,6 +8033,10 @@ class EquivalenceStrategy {
     );
   }
 
+  bool checkField_scope(EquivalenceVisitor visitor, Field node, Field other) {
+    return visitor.checkNodes(node.scope, other.scope, 'scope');
+  }
+
   bool checkMember_fileEndOffset(
     EquivalenceVisitor visitor,
     Member node,

pkg/kernel/lib/text/ast_to_text.dart

@@ -1345,6 +1345,9 @@ class Printer extends VisitorDefault<void> with VisitorVoidMixin {
     writeSpace();
     writeAnnotatedType(node.type, annotator?.annotateField(this, node));
     writeName(getMemberName(node), showLibrary: true);
+    if (node.scope case Scope scope?) {
+      writeScope(scope);
+    }
     Expression? initializer = node.initializer;
     if (initializer != null) {
       writeSpaced('=');