Adjust help message and add example

Author: royitaqi

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -616,8 +616,8 @@ void CommandInterpreter::LoadCommandDictionary() {
   std::unique_ptr<CommandObjectRegexCommand> break_regex_cmd_up(
       new CommandObjectRegexCommand(
           *this, "_regexp-break",
-          "List all breakpoints, or set a breakpoint using one of several "
-          "shorthand formats.",
+          "Set a breakpoint using one of several shorthand formats, or list "
+          "the existing breakpoints if no arguments are provided.",
           "\n"
           "_regexp-break <filename>:<linenum>:<colnum>\n"
           "              main.c:12:21          // Break at line 12 and column "
@@ -644,7 +644,10 @@ void CommandInterpreter::LoadCommandDictionary() {
           "              /break here/          // Break on source lines in "
           "current file\n"
           "                                    // containing text 'break "
-          "here'.\n",
+          "here'.\n"
+          "_regexp-break\n"
+          "                                    // List the existing "
+          "breakpoints\n",
           lldb::eSymbolCompletion | lldb::eSourceFileCompletion, false));
 
   if (break_regex_cmd_up) {