SI-8177 refine embeddedSymbols

We look for any prefix that has a refinement class for a type symbol.
This includes ThisTypes, which were not considered before.

pos/t8177g.scala, neg/t0764*scala now compile, as they should

Additional test cases contributed by Jason & Paul.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
index 2b5eed7102..02dd63f011 100644
--- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
+++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala
@@ -470,6 +470,8 @@ abstract class RefChecks extends InfoTransform with scala.reflect.internal.trans
           // Important: first check the pair has the same kind, since the substitution
           // carries high's type parameter's bounds over to low, so that
           // type equality doesn't consider potentially different bounds on low/high's type params.
+          // In b781e25afe this went from using memberInfo to memberType (now lowType/highType), tested by neg/override.scala.
+          // TODO: was that the right fix? it seems type alias's RHS should be checked by looking at the symbol's info
           if (pair.sameKind && lowType.substSym(low.typeParams, high.typeParams) =:= highType) ()
           else overrideTypeError() // (1.6)
         }