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, 1 insertions, 0 deletions

diff --git a/test/files/presentation/t8085b.flags b/test/files/presentation/t8085b.flags
new file mode 100644
index 0000000000..ec35b223d8
--- /dev/null
+++ b/test/files/presentation/t8085b.flags
@@ -0,0 +1 @@
+-sourcepath src