[new release] io-page (2.4.0)

CHANGES:

* Use workspace flags (@TheLortex, mirage/io-page#60)
* Use ocamlformat (@TheLortex, mirage/io-page#60)
* **breaking changes** Remove io-page-xen and io-page-unix split (@samoht, mirage/io-page#60)
* Update CI scripts (@samoht, mirage/io-page#60)
* **breaking changes** Update the C layout of io-page according MirageOS 3/4 (@dinosaure, mirage/io-page#62)
  JS/C functions are renamed from `mirage_*` to `caml_mirage_iopage_*`
* Add ocaml-freestanding and pkg-config as dependencies of `io-page`
  To be able to 'cross'-compile to Solo5

packages/io-page/io-page.2.4.0/opam

@@ -0,0 +1,43 @@
+opam-version: "2.0"
+maintainer: "anil@recoil.org"
+authors: ["Anil Madhavapeddy" "Dave Scott" "Thomas Gazagnaire"]
+license: "ISC"
+tags: "org:mirage"
+homepage: "https://github.com/mirage/io-page"
+bug-reports: "https://github.com/mirage/io-page/issues"
+doc: "https://mirage.github.io/io-page/"
+depends: [
+  "conf-pkg-config" {build}
+  "ocaml" {>= "4.02.3"}
+  "dune"
+  "cstruct" {>= "2.0.0"}
+  "bigarray-compat"
+  "ounit" {with-test}
+]
+build: [
+  ["dune" "subst"] {pinned}
+  ["dune" "build" "-p" name "-j" jobs]
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
+]
+conflicts: [
+  "mirage-xen" {< "6.0.0"}
+  "ocaml-freestanding" {< "0.4.1"}
+]
+depopts: [
+  "ocaml-freestanding"
+]
+dev-repo: "git+https://github.com/mirage/io-page.git"
+synopsis: "Support for efficient handling of I/O memory pages"
+description: """
+IO pages are page-aligned, and wrapped in the `Cstruct` library to avoid
+copying the data contained within the page.
+"""
+x-commit-hash: "5582368140ca17db68110a6fca34f593e043c8b1"
+url {
+  src:
+    "https://github.com/mirage/io-page/releases/download/v2.4.0/io-page-v2.4.0.tbz"
+  checksum: [
+    "sha256=ccc6486f321e4df4fbb0480c829df8260857a116bf0dc0aac9d0fd24e746382f"
+    "sha512=762c0ff4a7be4448688dc9208e56fd51d325dfb48d4e58100b83d554fa71dc8ab493317f8e2c877389309d19490bad39b84abb3afcd74e829b57da74375dc59f"
+  ]
+}