[sysprof] Created tag sysprof-3.21.91

[Christian Hergert <chergert src gnome org>]

The signed tag 'sysprof-3.21.91' was created.

Tagger: Christian Hergert <chergert redhat com>
Date: Thu Sep 1 21:34:42 2016 -0700

    release 3.21.91

Changes since the last tag 'sysprof-3.21.90':

Christian Hergert (5):
      util: add full memory barrier fallback
      build: use -std=gnu11 by default
      build: check for recent GCC with stdatomic.h
      callgraph-view: collapse row with Left Arrow
      release 3.21.91

Kalev Lember (1):
      build: Use correct gettext domain when installing translation files

Ray Strode (2):
      lib: use stdatomic.h for memory barriers
      lib: Add full barrier before writing data_tail