llvm-common: upgraded package to upstream

Upgraded sys-devel/llvm-common to version 6.0.0 on amd64, arm, x86

BUG=b:72153230
TEST=test_that --board=grunt graphics_SanAngeles
CQ-DEPEND=CL:1022080

Change-Id: Ie4f494be41c6048bca0fed126a67bd741553a266
Reviewed-on: https://chromium-review.googlesource.com/1022081
Commit-Ready: Drew Davenport <ddavenport@chromium.org>
Tested-by: Drew Davenport <ddavenport@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
4 files changed