cryptsetup: Provide implementation without cgo

internal/cryptsetup/BUILD.bazel

@@ -2,7 +2,10 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 
 go_library(
     name = "cryptsetup",
-    srcs = ["cryptsetup.go"],
+    srcs = [
+        "crypsetup_cross.go",
+        "cryptsetup_cgo.go",
+    ],
     # keep
     cdeps = [
         "@//rpm:cryptsetup",

internal/cryptsetup/crypsetup_cross.go

@@ -0,0 +1,15 @@
+//go:build !linux || !cgo
+
+/*
+Copyright (c) Edgeless Systems GmbH
+
+SPDX-License-Identifier: AGPL-3.0-only
+*/
+package cryptsetup
+
+const (
+	// ReadWriteQueueBypass is a flag to disable the write and read workqueues for a crypt device.
+	ReadWriteQueueBypass          = cryptActivateNoReadWorkqueue | cryptActivateNoWriteWorkqueue
+	cryptActivateNoReadWorkqueue  = 0x1000000
+	cryptActivateNoWriteWorkqueue = 0x2000000
+)

internal/cryptsetup/cryptsetup_cgo.go

@@ -1,3 +1,5 @@
+//go:build linux && cgo
+
 /*
 Copyright (c) Edgeless Systems GmbH