Revert "x86_64: remove special-case mappings for direct"
Revert "x86_64: remove special-case mappings for direct"

This reverts commit 052f7df430bab1f654e026f6443a1bacdbdfeb13.

Reason for revert: breaks tast.health.DiagnosticsRun.cpu_cache on volteer-manatee

Original change's description:
> x86_64: remove special-case mappings for direct
>
> Now that we can handle file-backed mappings that overlap with guest
> memory, we can remove the workarounds for coreboot regions when
> compiling with --features=direct.
>
> BUG=b:188011323
> TEST=cargo test -p x86_64 --features=direct
> TEST=Boot volteer-manatee and brya-manatee
>
> Change-Id: I9ac2a25e1896c5ec61bd302882d4c99d8b36b0dd
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3498210
> Reviewed-by: Junichi Uekawa <uekawa@chromium.org>
> Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
> Commit-Queue: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>

BUG=b:188011323
TEST=tast run health.DiagnosticsRun.cpu_cache

Change-Id: I313620d99726ed185ba2ec04df4413e43a612670
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3537260
Reviewed-by: Anton Romanov <7c8c28e1283c1d87f2c3df4d6b5c74b6ae02bcd9@google.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm