SI-8085 Fix BrowserTraverser for package objects

A source file like:

    import foo.bar
    package object baz

Is parsed into:

    package <empty> {
       import foo.bar
       package baz {
          object `package`
       }
    }

A special case in Namers compensates by adjusting the owner of
`baz` to be `<root>`, rather than `<empty>`.

This wasn't being accounted for in `BrowserTraverser`, which
underpins `-sourcepath`, and allows the presentation compiler to
load top level symbols from sources outside those passes as
the list of sources to compile.

This bug did not appear in sources like:

    package p1
    package object p2 { ... }

... because the parser does not wrap this in the `package <empty> {}`

This goes some way to explaining why it has gone unnoticed for
so long.

1 files changed, 2 insertions, 2 deletions

diff --git a/test/files/presentation/t8085.check b/test/files/presentation/t8085.check
index 46aac791f5..79c1b2aa17 100644
--- a/test/files/presentation/t8085.check
+++ b/test/files/presentation/t8085.check
@@ -1,3 +1,3 @@
 reload: NodeScalaSuite.scala
-prefixes differ: <empty>.nodescala,nodescala
-value always is not a member of object scala.concurrent.Future
+open package module: package nodescala
+Test OK