Merge "Export clang header for the build-tools sdk-repo build" am: def3a7e40a am: dcd0be3ce5 am: 4bb41194e5 am: 70a1fcf5cb am: 45042ac0c7

Original change: https://android-review.googlesource.com/c/platform/external/clang/+/1828413

Change-Id: Ia8fc32236b27ca431acb230a734226ca2d9108fc