Merge remote-tracking branch 'remotes/rth/tags/pull-sh4-20180709' into staging

Fix translation for gUSA regions.

# gpg: Signature made Mon 09 Jul 2018 18:46:02 BST
# gpg:                using RSA key 64DF38E8AF7E215F
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>"
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth/tags/pull-sh4-20180709:
  target/sh4: Fix translator.c assertion failure for gUSA

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>