First versions of Definitions based on TypeRefs not Symbols.

Symbols are not stable between runs, so if some symbol referred
to from Definitions gets recompiled, there are then two Symbols
that are both visible, one referenced from Definitions, the other
the one that got compiled.

Thos led to a crash when e.g. compiling scala.Short, because the
newly compiled symbol was not recognized as a primitive value
class.

The present commit tries to make systematic changes without regard
to simplicity or aesthetics. This will be polished in future commits.
// ### comments signal areas that need further attention.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/dotty/tools/dotc/printing/PlainPrinter.scala b/src/dotty/tools/dotc/printing/PlainPrinter.scala
index 5daef9fb8..8b2d68570 100644
--- a/src/dotty/tools/dotc/printing/PlainPrinter.scala
+++ b/src/dotty/tools/dotc/printing/PlainPrinter.scala
@@ -245,10 +245,10 @@ class PlainPrinter(_ctx: Context) extends Printer {
     }
   }
 
-  protected def isOmittablePrefix(sym: Symbol) =
-    (defn.UnqualifiedOwners contains sym) || isEmptyPrefix(sym)
+  protected def isOmittablePrefix(sym: Symbol): Boolean =
+    defn.UnqualifiedOwnerTypes.exists(_.symbol == sym) || isEmptyPrefix(sym)
 
-  protected def isEmptyPrefix(sym: Symbol) =
+  protected def isEmptyPrefix(sym: Symbol): Boolean =
     sym.isEffectiveRoot || sym.isAnonymousClass || sym.name.isReplWrapperName
 
   /** String representation of a definition's type following its name,