Fix handling of RetainedInline when compiling from tasty

Author: odersky

compiler/src/dotty/tools/dotc/transform/Erasure.scala

@@ -938,11 +938,7 @@ object Erasure {
           val origName = retainer.name.asTermName.exclude(BodyRetainerName)
           val targetName =
             if retainer.hasAnnotation(defn.TargetNameAnnot) then
-              try retainer.erasedName
-              finally
-                 // reset target name so that definition will have a BodyRetainerName
-                 // after erasure and be thereby eliminated in typedDefDef
-                retainer.setTargetName(retainer.name)
+              retainer.erasedName.unmangle(BodyRetainerName).exclude(BodyRetainerName)
             else origName
           val inlineMeth = atPhase(typerPhase) {
             retainer.owner.info.decl(origName)

compiler/src/dotty/tools/dotc/typer/Inliner.scala

@@ -17,6 +17,7 @@ import Contexts._
 import Names.{Name, TermName}
 import NameKinds.{InlineAccessorName, InlineBinderName, InlineScrutineeName, BodyRetainerName}
 import ProtoTypes.selectionProto
+import Annotations.Annotation
 import SymDenotations.SymDenotation
 import Inferencing.isFullyDefined
 import config.Printers.inlining
@@ -198,8 +199,10 @@ object Inliner {
       name = BodyRetainerName(meth.name),
       flags = meth.flags &~ (Inline | Macro | Override) | Private,
       coord = mdef.rhs.span.startPos).asTerm
-    for targetAnnot <- meth.getAnnotation(defn.TargetNameAnnot) do
-      retainer.addAnnotation(targetAnnot)
+    if meth.hasAnnotation(defn.TargetNameAnnot) then
+      retainer.addAnnotation(
+        Annotation(defn.TargetNameAnnot,
+          Literal(Constant(BodyRetainerName(meth.erasedName.asTermName).toString)).withSpan(meth.span)))
     polyDefDef(retainer, targs => prefss =>
       inlineCall(
         ref(meth).appliedToTypes(targs).appliedToArgss(prefss)