Revert "Improve failure message of enum fromOrdinal/valueOf"

This reverts commit 2dcd64a.

This caused the `parallelBackend` tests to loop forever.

Fixes #19285
Fixes #19281
Fixes #19278

compiler/src/dotty/tools/dotc/ast/DesugarEnums.scala

@@ -126,7 +126,7 @@ object DesugarEnums {
 
     val valuesOfBody: Tree =
       val defaultCase =
-        val msg = Apply(Select(Literal(Constant(s"enum ${enumClass.fullName} has no case with name: ")), nme.PLUS), Ident(nme.nameDollar))
+        val msg = Apply(Select(Literal(Constant("enum case not found: ")), nme.PLUS), Ident(nme.nameDollar))
         CaseDef(Ident(nme.WILDCARD), EmptyTree,
           Throw(New(TypeTree(defn.IllegalArgumentExceptionType), List(msg :: Nil))))
       val stringCases = enumValues.map(enumValue =>
@@ -148,8 +148,7 @@ object DesugarEnums {
     def valueCtor: List[Tree] = if constraints.requiresCreator then enumValueCreator :: Nil else Nil
     def fromOrdinal: Tree =
       def throwArg(ordinal: Tree) =
-        val msg = Apply(Select(Literal(Constant(s"enum ${enumClass.fullName} has no case with ordinal: ")), nme.PLUS), Select(ordinal, nme.toString_))
-        Throw(New(TypeTree(defn.NoSuchElementExceptionType), List(msg :: Nil)))
+        Throw(New(TypeTree(defn.NoSuchElementExceptionType), List(Select(ordinal, nme.toString_) :: Nil)))
       if !constraints.cached then
         fromOrdinalMeth(throwArg)
       else

tests/run/enum-java.check

@@ -26,7 +26,7 @@ MONDAY : 0
 TUESDAY : 1
 SATURDAY : 2
 By-name value: MONDAY
-Correctly failed to retrieve illegal name, message: enum A has no case with name: stuff
+Correctly failed to retrieve illegal name, message: enum case not found: stuff
 
 Collections Test
 Retrieving Monday: workday

tests/run/enum-values.scala

@@ -61,7 +61,7 @@ enum ClassOnly: // this should still generate the `ordinal` and `fromOrdinal` co
     catch
       case e: java.lang.reflect.InvocationTargetException => // TODO: maybe reflect.Selectable should catch this?
         assert(e.getCause.isInstanceOf[java.util.NoSuchElementException]
-          && e.getCause.getMessage == s"enum ${companion.getClass.getName.stripSuffix("$")} has no case with ordinal: $ordinal")
+          && e.getCause.getMessage == ordinal.toString)
 
   fetchFromOrdinal(companion = Color,       compare = Red, Green, Blue)
   fetchFromOrdinal(companion = Suits,       compare = Clubs, Spades, Diamonds, Hearts)

tests/run/enums-java-compat.check

@@ -6,4 +6,4 @@ TUESDAY : 1
 SATURDAY : 2
 Stuff : 3
 By-name value: MONDAY
-Correctly failed to retrieve illegal name, message: enum A has no case with name: stuff
+Correctly failed to retrieve illegal name, message: enum case not found: stuff