Revert "Revert "Added optimized CRC32 algorithm.""

This reverts commit 1e90cbf92cf34669ddb9ce8c7ea093b8c8b25523.
Revert "Revert "android/lowmemorykiller: Ignore tasks with freed mm""

This reverts commit 169ce515984c283f0dcce125f02643b9e31ca12c.