Fix completion for synthetic case modules and methods

I'm pretty sure the `isSynthetic` call added in 854de25ee6 should
instead be `isArtifact`, so that's what I've implemented here.

`isSynthetic` used to also filter out error symbols, which are
created with the flags `SYNTHETIC | IS_ERROR`. I've added an addition
test for `isError`, which was needed to keep the output of
`presentation/scope-completion-import` unchanged.

The checkfile for `presentation/callcc-interpreter` is modified to
add the additional completion proposals: synthetic companion objects.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/interactive/scala/tools/nsc/interactive/Global.scala b/src/interactive/scala/tools/nsc/interactive/Global.scala
index 6c8719b5eb..d6be6331ce 100644
--- a/src/interactive/scala/tools/nsc/interactive/Global.scala
+++ b/src/interactive/scala/tools/nsc/interactive/Global.scala
@@ -1000,7 +1000,7 @@ class Global(settings: Settings, _reporter: Reporter, projectName: String = "")
     def add(sym: Symbol, pre: Type, implicitlyAdded: Boolean)(toMember: (Symbol, Type) => M) {
       if ((sym.isGetter || sym.isSetter) && sym.accessed != NoSymbol) {
         add(sym.accessed, pre, implicitlyAdded)(toMember)
-      } else if (!sym.name.decodedName.containsName("$") && !sym.isSynthetic && sym.hasRawInfo) {
+      } else if (!sym.name.decodedName.containsName("$") && !sym.isError && !sym.isArtifact && sym.hasRawInfo) {
         val symtpe = pre.memberType(sym) onTypeError ErrorType
         matching(sym, symtpe, this(sym.name)) match {
           case Some(m) =>