Revert "Revert "Revert "Revert "[optimizing] Improve x86 shifts""""

This reverts commit 2a7a1d7808f003bea908023ebd11eb442d2fca39.

Fix the problem that a long long >> 63 got the wrong answer.  The
problem was that a shr was used instead of a sar.

Change-Id: I0327f79c718016ddec9272a605fc50ec15ec4566
4 files changed