Rebase gemmlowp to a227af1fdb47f250b5df07d6936366b0f8113b65 am: 70ba50cbca am: 36f90a2b7a am: 846c903a24 am: e8a1111f83
am: 68dcc597e6

Change-Id: I3b8e5f4357c374dc32ffc1fa075642bba59401c5