Revert specific conversion checking

Author: odersky

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

@@ -648,14 +648,11 @@ object Checking {
           else "Cannot override non-inline parameter with an inline parameter",
           p1.srcPos)
 
-  def checkConversionsSpecific(from: Type, to: Type, pos: SrcPos)(using Context): Unit =
-    def fail(part: String, tp: Type) =
-      report.error(em"the $part of an implicit conversion must be more specific than $tp", pos)
+  def checkConversionsSpecific(to: Type, pos: SrcPos)(using Context): Unit =
     if to.isRef(defn.AnyValClass, skipRefined = false)
        || to.isRef(defn.ObjectClass, skipRefined = false)
-    then fail("result", to)
-    if from.isBottomTypeAfterErasure
-    then fail("argument", from)
+    then
+      report.error(em"the result of an implicit conversion must be more specific than $to", pos)
 }
 
 trait Checking {

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

@@ -3579,7 +3579,7 @@ class Typer extends Namer
             else tree
           else tree // other adaptations for selections are handled in typedSelect
         case _ if ctx.mode.is(Mode.ImplicitsEnabled) && tree.tpe.isValueType =>
-          checkConversionsSpecific(wtp, pt, tree.srcPos)
+          checkConversionsSpecific(pt, tree.srcPos)
           inferView(tree, pt) match
             case SearchSuccess(found, _, _, isExtension) =>
               if isExtension then found