Fix #7428: Don't make enum values JavaStatic

It leads to backend crashes if the enum is defined in a class and does
not seem to be needed anyway.

Author: odersky

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

@@ -526,7 +526,7 @@ object Flags {
   val DeferredOrLazyOrMethod: FlagSet        = Deferred | Lazy | Method
   val DeferredOrTermParamOrAccessor: FlagSet = Deferred | ParamAccessor | TermParam           // term symbols without right-hand sides
   val DeferredOrTypeParam: FlagSet           = Deferred | TypeParam                           // type symbols without right-hand sides
-  val EnumValue: FlagSet                     = Enum | JavaStatic | StableRealizable           // A Scala enum value
+  val EnumValue: FlagSet                     = Enum | StableRealizable           // A Scala enum value
   val StableOrErased: FlagSet                = Erased | StableRealizable                      // Assumed to be pure
   val ExtensionMethod: FlagSet               = Extension | Method
   val FinalOrInline: FlagSet                 = Final | Inline

tests/pos/i7428.scala

@@ -0,0 +1,6 @@
+object ABug
+  enum Tag
+    case first
+  import Tag.first
+  val xx = first
+