More uniform treatment of package objects

  - Introduce `Symbol#packageObject` and `Type#packageObject`
    to lookup the member package object of a package class/module,
    and use this far and wide.
  - Replace the overly complicated (and still buggy) implementation
    of `Context#isInPackageObject` with a one liner. The simplifying
    insight is that if we select a symbol from a package prefix
    that does not own that symbol, it *must* have really been
    selected from the package object.
  - Change implicit search to use the cache in
    `ModuleSymbol#implicitMembers` via `Type#implicitMembers`,
    which lets the client code read more naturally.

Fixes a bug with `adapt::insertApply` that Adriaan spotted in a feat
of lateral thinking. This is tested in t8862b.scala. alladin763.scala
adds the test case from the bug originally remedied by `insertApply`
to check we haven't regressed.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/reflect/scala/reflect/internal/TreeGen.scala b/src/reflect/scala/reflect/internal/TreeGen.scala
index 6e8e992d16..6ddd49045c 100644
--- a/src/reflect/scala/reflect/internal/TreeGen.scala
+++ b/src/reflect/scala/reflect/internal/TreeGen.scala
@@ -191,8 +191,8 @@ abstract class TreeGen {
       )
       val pkgQualifier =
         if (needsPackageQualifier) {
-          val packageObject = rootMirror.getPackageObjectWithMember(qual.tpe, sym)
-          Select(qual, nme.PACKAGE) setSymbol packageObject setType singleType(qual.tpe, packageObject)
+          val packageObject = qualsym.packageObject
+          Select(qual, nme.PACKAGE) setSymbol packageObject setType packageObject.typeOfThis
         }
         else qual