CI: Add native and bytecode workflows using MSVC

Add a native workflow and a bytecode one using MSVC
Run the bytecode-only in two parts, like Cygwin
Use the current bleeding edge versions of dune and QCheck as they
recently merged fixes that are relevant for these workflows
Add badges for those two new workflows

.github/workflows/msvc-bytecode.yml

@@ -0,0 +1,19 @@
+name: MSVC bytecode CI workflow
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  part1:
+    uses: ./.github/workflows/msvc-common.yml
+    with:
+      bytecodeonly: true
+      dune_alias: 'ci1'
+
+  part2:
+    needs: part1
+    # Run part2 even if some test failed in part1:
+    if: ${{ always() }}
+    uses: ./.github/workflows/msvc-common.yml
+    with:
+      bytecodeonly: true
+      dune_alias: 'ci2'

.github/workflows/msvc-common.yml

@@ -0,0 +1,144 @@
+name: Common MSVC CI workflow
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+on:
+  workflow_call:
+    inputs:
+      bytecodeonly:
+        type: boolean
+        default: false
+      dune_alias:
+        description: 'dune alias that should be built in the main step'
+        type: string
+        default: 'runtest'
+
+jobs:
+  build:
+    permissions: {}
+
+    runs-on: windows-latest
+
+    steps:
+      - name: Save pristine PATH
+        id: pristine
+        run: |
+          echo "pristine_path=${env:Path}" >> "${env:GITHUB_OUTPUT}"
+
+      - name: Set up MSVC
+        uses: ilammy/msvc-dev-cmd@v1
+
+      - name: Fetch OCaml
+        uses: actions/checkout@v4
+        with:
+          repository: dra27/ocaml
+          ref: restore-msvc
+          path: ocaml
+          submodules: true
+
+      - name: Choose a cache key
+        id: key
+        env:
+          BC_KEY_PART: ${{ inputs.bytecodeonly && '-bytecode' || '' }}
+        run: |
+          git -C ocaml rev-parse HEAD | Tee-Object -Variable sha
+          echo "cache_key=ocaml-msvc${env:BC_KEY_PART}-${sha}" | Tee-Object -FilePath "${env:GITHUB_OUTPUT}"
+
+      - name: Restore cache
+        uses: actions/cache/restore@v3
+        id: cache
+        env:
+          PATH: ${{ steps.pristine.outputs.pristine_path }}
+        with:
+          path: |
+            C:\cygwin-packages
+            D:\ocaml
+          key: ${{ steps.key.outputs.cache_key }}
+
+      - name: Install Cygwin (Cygwin)
+        uses: cygwin/cygwin-install-action@v3
+        with:
+          packages: make,bash
+          install-dir: 'D:\cygwin'
+
+      - name: Build OCaml
+        shell: bash -e {0}
+        env:
+          NATIVE: ${{ inputs.bytecodeonly && '--disable-native-compiler' || '' }}
+        run: |
+          cd ocaml                                                                               #
+          mkdir /cygdrive/d/ocaml                                                                #
+          eval $(tools/msvs-promote-path)                                                        #
+          ./configure --host=x86_64-pc-windows --with-flexdll --prefix=/cygdrive/d/ocaml $NATIVE #
+          make                                                                                   #
+          make install                                                                           #
+        if: "steps.cache.outputs.cache-hit != 'true'"
+
+      - name: Fetch dune
+        uses: actions/checkout@v4
+        with:
+          repository: ocaml/dune
+          path: dune
+        if: "steps.cache.outputs.cache-hit != 'true'"
+
+      - name: Compile dune
+        shell: bash -e {0}
+        run: |
+          export PATH="/cygdrive/d/ocaml/bin:$PATH"                                        #
+          eval $(ocaml/tools/msvs-promote-path)                                            #
+          export INCLUDE="$INCLUDE;$(cygpath -w "$PWD/ocaml/runtime/winpthreads/include")" #
+          cd dune                                                                          #
+          make release                                                                     #
+          make install PREFIX='D:\ocaml'                                                   #
+        if: "steps.cache.outputs.cache-hit != 'true'"
+
+      - name: Display configuration and set up PATH
+        run: |
+          D:\ocaml\bin\ocamlc -config
+          D:\ocaml\bin\dune --version
+          echo "D:\ocaml\bin" >> ${env:GITHUB_PATH}
+
+      - name: Save cache
+        uses: actions/cache/save@v3
+        env:
+          PATH: ${{ steps.pristine.outputs.pristine_path }}
+        with:
+          path: |
+            C:\cygwin-packages
+            D:\ocaml
+          key: ${{ steps.key.outputs.cache_key }}
+        if: "steps.cache.outputs.cache-hit != 'true'"
+
+      - name: Fetch multicoretests
+        uses: actions/checkout@v4
+        with:
+          path: mct
+
+      - name: Fetch QCheck
+        uses: actions/checkout@v4
+        with:
+          repository: c-cube/qcheck
+          path: mct/qcheck
+
+      - name: Build the test suite
+        shell: bash -e {0}
+        run: |
+          eval $(ocaml/tools/msvs-promote-path)     #
+          cd mct                                    #
+          dune build                                #
+          dune build test/                          #
+
+      - name: Run the internal package tests
+        run: |
+          cd mct
+          dune runtest -j1 --no-buffer --display=quiet --cache=disabled --error-reporting=twice test/
+
+      - name: Run the multicore test suite
+        env:
+          QCHECK_MSG_INTERVAL: 60
+          DUNE_CI_ALIAS:       ${{ inputs.dune_alias }}
+        run: |
+          cd mct
+          dune build "@ci" -j1 --no-buffer --display=quiet --cache=disabled --error-reporting=twice

.github/workflows/msvc-native.yml

@@ -0,0 +1,7 @@
+name: MSVC native CI workflow
+
+on: [push, pull_request, workflow_dispatch]
+
+jobs:
+  build:
+    uses: ./.github/workflows/msvc-common.yml

README.md

@@ -31,6 +31,9 @@ Multicore tests
 [![Windows 5.2.0+trunk-bytecode](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-520-trunk-bytecode.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/windows-520-trunk-bytecode.yml)
 [![Cygwin 5.2.0+trunk](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin-520-trunk.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/cygwin-520-trunk.yml)
 
+[![MSVC native](https://github.com/ocaml-multicore/multicoretests/actions/workflows/msvc-native.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/msvc-native.yml)
+[![MSVC bytecode](https://github.com/ocaml-multicore/multicoretests/actions/workflows/msvc-bytecode.yml/badge.svg)](https://github.com/ocaml-multicore/multicoretests/actions/workflows/msvc-bytecode.yml)
+
 Property-based tests of (parts of) the OCaml multicore compiler and run time.
 
 This project contains