compiler-wrapper: adds an IWYU component

This first patch makes it possible to run IWYU as a part of the build
process. It's not currently possible for us to make changes to packages:
this functionality will appear in a later CL.

BUG=b:237320348
TEST=Tested locally

Change-Id: I00610284143cf478b242b2c0ca1c05e2c8d43de4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3820351
Reviewed-by: Ryan Beltran <ryanbeltran@chromium.org>
Auto-Submit: Christopher Di Bella <cjdb@google.com>
Commit-Queue: Ryan Beltran <ryanbeltran@chromium.org>
Tested-by: Christopher Di Bella <cjdb@google.com>
7 files changed