Include <vector> in WatchpointResource.h

On macOS <vector> was already included via another
header file, but this failed on the CI bots.  I'd
tested on linux earlier in this patch's life when
the headers were differently arranged.

Author: jasonmolenda

lldb/include/lldb/Breakpoint/WatchpointResource.h

@@ -13,7 +13,7 @@
 #include "lldb/lldb-public.h"
 
 #include <mutex>
-#include <set>
+#include <vector>
 
 namespace lldb_private {