o/blockdev: add windows implementation

This adds a relatively bare bones, but working implementation of
blockdev for Windows.  Has been manually tested on Windows 23H2.

Change-Id: I7a2bf0a46e973f838506a321ad815629f62a3b35
Reviewed-on: https://review.monogon.dev/c/monogon/+/3696
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Vouch-Run-CI: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/osbase/blockdev/BUILD.bazel b/osbase/blockdev/BUILD.bazel
index f476e8b..a720d80 100644
--- a/osbase/blockdev/BUILD.bazel
+++ b/osbase/blockdev/BUILD.bazel
@@ -7,6 +7,7 @@
         "blockdev.go",
         "blockdev_darwin.go",
         "blockdev_linux.go",
+        "blockdev_windows.go",
         "memory.go",
     ],
     importpath = "source.monogon.dev/osbase/blockdev",
@@ -24,6 +25,9 @@
         "@io_bazel_rules_go//go/platform:linux": [
             "@org_golang_x_sys//unix",
         ],
+        "@io_bazel_rules_go//go/platform:windows": [
+            "@org_golang_x_sys//windows",
+        ],
         "//conditions:default": [],
     }),
 )