compiler: only import variable into . if same package

If we dot-import a package, we should only add an imported variable to
the package bindings if the variable is in the package being imported.
A test case for this is the 1.13 os package, in which ErrClosed and
friends are defined both locally and in the imported internal/oserror package.

Change-Id: I43e1a08cafa5e6136a82194d32f3deb23bec7d69
Reviewed-by: Cherry Zhang <>
1 file changed