Fix mapping of annotations containing defs

compiler/src/dotty/tools/dotc/core/Annotations.scala

@@ -62,7 +62,7 @@ object Annotations {
             if tm.isRange(x) then x
             else
               val tp1 = tm(tree.tpe)
-              foldOver(if tp1 frozen_=:= tree.tpe then x else tp1, tree)
+              foldOver(if tp1 eq tree.tpe then x else tp1, tree)
         val diff = findDiff(NoType, args)
         if tm.isRange(diff) then EmptyAnnotation
         else if diff.exists then derivedAnnotation(tm.mapOver(tree))

tests/printing/dependent-annot-19846.check

@@ -0,0 +1,33 @@
+[[syntax trees at end of                     typer]] // tests/printing/dependent-annot-19846.scala
+package <empty> {
+  class lambdaAnnot(g: () => Int) extends scala.annotation.Annotation(),
+    annotation.StaticAnnotation {
+    private[this] val g: () => Int
+  }
+  final lazy module val Test: Test = new Test()
+  final module class Test() extends Object() { this: Test.type =>
+    val y: Int = ???
+    val z:
+      Int @lambdaAnnot(
+        {
+          def $anonfun(): Int = Test.y
+          closure($anonfun)
+        }
+      )
+     = f(Test.y)
+  }
+  final lazy module val dependent-annot-19846$package:
+    dependent-annot-19846$package = new dependent-annot-19846$package()
+  final module class dependent-annot-19846$package() extends Object() {
+    this: dependent-annot-19846$package.type =>
+    def f(x: Int):
+      Int @lambdaAnnot(
+        {
+          def $anonfun(): Int = x
+          closure($anonfun)
+        }
+      )
+     = x
+  }
+}
+

tests/printing/dependent-annot-19846.scala

@@ -0,0 +1,5 @@
+class lambdaAnnot(g: () => Int) extends annotation.StaticAnnotation
+def f(x: Int): Int @lambdaAnnot(() => x) = x
+object Test:
+  val y: Int = ???
+  val z /*: Int @lambdaAnnot(() => y) */ = f(y)