splitview.addView should set low prio to new view

src/vs/base/browser/ui/splitview/splitview.css

@@ -20,4 +20,5 @@
 
 .monaco-split-view2.horizontal > .split-view-view {
 	height: 100%;
+	display: inline-block;
 }

src/vs/base/browser/ui/splitview/splitview.ts

@@ -161,7 +161,7 @@ export class SplitView implements IDisposable {
 		}
 
 		view.render(container, this.orientation);
-		this.relayout();
+		this.relayout(index);
 		this.state = State.Idle;
 	}