gdb: Use vector::emplace_back

Now that we require C++11, we can use vector::emplace_back to
construct elements in place instead of constructing and then copying.

gdb/ChangeLog:
2016-11-09  Pedro Alves  <palves@redhat.com>

	* main.c (struct cmdarg): Add constructor.
	(captured_main_1): Use vector::emplace_back.
	* tracepoint.c (collection_list::add_memrange): Likewise.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index 3d28606eab..2a40b16755 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -919,7 +919,7 @@ collection_list::add_memrange (int type, bfd_signed_vma base,
   /* type: memrange_absolute == memory, other n == basereg */
   /* base: addr if memory, offset if reg relative.  */
   /* len: we actually save end (base + len) for convenience */
-  m_memranges.push_back (memrange (type, base, base + len));
+  m_memranges.emplace_back (type, base, base + len);
 
   if (type != memrange_absolute)    /* Better collect the base register!  */
     add_register (type);