8261931: IGV: quick search fails on multi-line node labels

Remove line breaks from the 'label' property that is searched on by default.

Reviewed-by: neliasso, xliu, chagedorn

src/utils/IdealGraphVisualizer/Graph/src/com/sun/hotspot/igv/graph/Figure.java

@@ -279,7 +279,7 @@ public String[] getLines() {
             // class NodeQuickSearch in the View module.
             for (InputNode n : getSource().getSourceNodes()) {
                 String label = resolveString(diagram.getNodeText(), n.getProperties());
-                n.getProperties().setProperty("label", label);
+                n.getProperties().setProperty("label", label.replaceAll("\\R", " "));
             }
         }
         return lines;