cmd/cue: add newline between imported objects

Signed-off-by: Marcel van Lohuizen <mpvl@golang.org>

Change-Id: Ie537e739d8ea1a616a45677352fde090090fcc10
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/532275
Unity-Result: CUEcueckoo <cueckoo@cuelang.org>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Reviewed-by: Paul Jolly <paul@myitcv.io>

cmd/cue/cmd/orphans.go

@@ -220,6 +220,7 @@ func placeOrphans(b *buildPlan, d *encoding.Decoder, pkg string, objs ...*ast.Fi
 							astinternal.DebugStr(x), arg)
 					}
 				}
+				ast.SetPos(label, token.NoPos)
 				a = append(a, cue.Label(label))
 				labels = append(labels, label)
 			}

cmd/cue/cmd/testdata/script/import_merge.txt

@@ -0,0 +1,21 @@
+cue import -o - x.yaml -l objects: -l metadata.name
+cmp stdout expect-stdout
+
+-- x.yaml --
+kind: "foo"
+metadata:
+  name: foo
+---
+kind: "foo"
+metadata:
+  name: bar
+
+-- expect-stdout --
+objects: foo: {
+	kind: "foo"
+	metadata: name: "foo"
+}
+objects: bar: {
+	kind: "foo"
+	metadata: name: "bar"
+}