bzip2: Fix an issue with shift caught by ubsan.

Apply the patch already sent/applied in Gentoo.

https://github.com/gentoo/gentoo/commit/66f614c51f017b0693f5aaeb5897db28ef3aff6c

Patch details:
Use unsigned 1 for shifting instead of signed 1.

This fixed an issue with shift caught by undefined behavior
sanitizer in clang.
bzip2-1.0.6/blocksort.c:255:7
runtime error: left shift of 1 by 31 places cannot be represented in type 'int'

BUG=chromium:877236
TEST=bzip2 builds.

Change-Id: If9de5b5d5b1dd2f676b8921fe19cec4a6e8c4430
Reviewed-on: https://chromium-review.googlesource.com/1188822
Tested-by: Manoj Gupta <manojgupta@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Manoj Gupta <manojgupta@chromium.org>
2 files changed