Fix windows build. It does not like mixed 'enum' and 'enum class'.

[andrewford]

Summary

Change-Id: I611460cf4df58073bda64e16847e5358c3361aa7

[andrewford]

BTW, I don't have commit access, would appreciate if someone could submit for me assuming this is acceptable :)

include/lldb/Breakpoint/BreakpointOptions.h

enum class OptionNames {
     ConditionText = 0,
     IgnoreCount,
     EnabledState,
     OneShotState,
     LastOptionName
   };
   static const char *g_option_names[(size_t) OptionNames::LastOptionName];
 
-  static const char *GetKey(enum OptionNames enum_value) {
+  static const char *GetKey(OptionNames enum_value) {
     return g_option_names[(size_t) enum_value];
   }
 
   static bool BreakpointOptionsCallbackFunction(
       void *baton, StoppointCallbackContext *context, lldb::user_id_t break_id,
       lldb::user_id_t break_loc_id);
       
   void SetThreadSpec(std::unique_ptr<ThreadSpec> &thread_spec_up);