Big realizability refactoring

Move logic from TypeOps to new file CheckRealizable.scala.
Also check realizable fields under strict mode.
Check at phase PostTyper rather than Typer to avoid cycles.
New tests for imports and deep paths.

1 files changed, 31 insertions, 0 deletions

diff --git a/tests/neg/i1050c.scala b/tests/neg/i1050c.scala
new file mode 100644
index 000000000..ece1f9986
--- /dev/null
+++ b/tests/neg/i1050c.scala
@@ -0,0 +1,31 @@
+// i1050 checks failing at typer
+object Import {
+    trait A { type L <: Nothing }
+    trait B { type L >: Any}
+    trait U {
+      lazy val p: B
+      locally { val x: p.L = ??? } // error: nonfinal lazy
+      locally {
+        import p._
+        val x: L = ??? // error: nonfinal lazy
+      }
+    }
+}
+object Tiark4 {
+    trait U {
+      type Y
+      trait X { type L = Y }
+      def compute: X
+      final lazy val p: X = compute
+      def brand(x: Y): p.L = x
+    }
+    trait V extends U {
+      type Y >: Any <: Nothing
+      def compute: X = ???
+    }
+    val v = new V {} // error: cannot be instantiated
+    v.brand("boom!")
+}
+object V { // error: cannot be instantiated
+  type Y >: Any <: Nothing  // error: only classes can have declared but undefined members
+}