Debugger: Handle double click of sub break points

Double clicking on a child break point (e.g. multi location
break point) now jumps to the respective parent break point.

Change-Id: I93497f8eec78408909dddd159002e171805814d7
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/debugger/breakhandler.cpp

@@ -1943,6 +1943,8 @@ bool BreakHandler::setData(const QModelIndex &idx, const QVariant &value, int ro
                     editBreakpoints({b}, ev.view());
                 else
                     b.gotoLocation();
+            } else if (LocationItem *l = itemForIndexAtLevel<2>(idx)) {
+                Breakpoint(l->parent()).gotoLocation();
             } else {
                 addBreakpoint();
             }