Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160804' into staging

Merge remote-tracking branch 'remotes/riku/tags/pull-linux-user-20160804' into staging

linux-user important fixes for 2.7

# gpg: Signature made Thu 04 Aug 2016 15:10:57 BST
# gpg:                using RSA key 0xB44890DEDE3C9BC0
# gpg: Good signature from "Riku Voipio <[email protected]>"
# gpg:                 aka "Riku Voipio <[email protected]>"
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* remotes/riku/tags/pull-linux-user-20160804:
  linux-user: Handle brk() attempts with very large sizes
  linux-user: Fix target_semid_ds structure definition
  linux-user: Don't write off end of new_utsname buffer
  linux-user: Fix memchr() argument in open_self_cmdline()
  linux-user: Use correct alignment for long long on i386 guests

Signed-off-by: Peter Maydell <[email protected]>