tree fa458a112b3672ee55b89ac1b61a2d02e0cecede
parent 0ba9b299e957d4ecb476386fa9b9f1624fd83ab7
author Tom Finegan <tomfinegan@google.com> 1464365795 -0700
committer Tom Finegan <tomfinegan@google.com> 1464366191 -0700

vpx_ports/mem_ops.h: cast the lhs of bitwise shifts of 24.

C does not allow for shifting into the sign bit of a signed
integer, and the two instances here become signed ints via
promotion. Explcitly cast them to unsigned MEM_VALUE_T to
avoid the problem.

BUG=https://bugs.chromium.org/p/chromium/issues/detail?id=614648

Change-Id: I51165361a8c6cbb5c378cf7e4e0f4b80b3ad9a6e