Change definition of isLegalPrefix so that it allows projecting on an abstract type.

This is needed to make the encoding og higher-kinded types work. E.g.

    Rep[Int]

would be represented as

    Rep { type Arg$0 = Int } # Apply

where Apply is an abstract member of the base class Lambfa$I of Rep.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/neg/projections.scala b/tests/neg/projections.scala
new file mode 100644
index 000000000..5d80e1151
--- /dev/null
+++ b/tests/neg/projections.scala
@@ -0,0 +1,7 @@
+class projections {
+
+  class Lambda { type Arg; type Apply }
+
+  var x: (Lambda { type Apply = Int }) # Apply = _ // error: illegal prefix
+
+}