Use std::move in a few places

This patch adds std::move to few spots where it seems to be missing.

Regression tested by the buildbot.

ChangeLog
2017-08-14  Tom Tromey  <tom@tromey.com>

	* break-catch-throw.c (handle_gnu_v3_exceptions): Use std::move.
	* break-catch-syscall.c (create_syscall_event_catchpoint): Use
	std::move.
	* break-catch-sig.c (create_signal_catchpoint): Use std::move.

gdb/break-catch-syscall.c

@@ -375,7 +375,7 @@ create_syscall_event_catchpoint (int tempflag, std::vector<int> &&filter,
 
   c = new syscall_catchpoint ();
   init_catchpoint (c, gdbarch, tempflag, NULL, ops);
-  c->syscalls_to_be_caught = filter;
+  c->syscalls_to_be_caught = std::move (filter);
 
   install_breakpoint (0, c, 1);
 }