Fix #1990: Handle case where inlining changes class of outer

The new situation in the test was that outer of the inlined method
was `A` but it's as seen from type is a subtype `B`.

We need two fixes:

 - Ignore outerSelects in TreeChecker. These are treated as having fixed symbols.
 - Adapt the outer-path logic to deal with code that's moved to another context.

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/pos/i1990.scala b/tests/pos/i1990.scala
new file mode 100644
index 000000000..77cea0af7
--- /dev/null
+++ b/tests/pos/i1990.scala
@@ -0,0 +1,12 @@
+class A {
+  class Foo {
+    inline def inlineMeth: Unit = {
+      new Bar
+    }
+  }
+  class Bar
+}
+
+class B extends A {
+  (new Foo).inlineMeth
+}