dev-lang/{rust, rust-host}: BDEPEND on llvm

This will make sure the llvm-project inside Rust builds with the regular
ebuild clang, not the bootstrap clang. This is necessary to make sure
the profdata generated for PGO is supported.

BUG=b:237786394,b:242227982

Change-Id: I311f9b5eff2ae3d1b23194a6337a02a55daa1013
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/3831382
Tested-by: Michael Benfield <mbenfield@google.com>
Reviewed-by: George Burgess <gbiv@chromium.org>
2 files changed