src: add build Github Action

Backport-PR-URL: #32608
PR-URL: #31153
Reviewed-By: Christian Clauss <cclauss@me.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

.github/workflows/CI.yml

@@ -0,0 +1,43 @@
+name: CI
+
+on: [push, pull_request]
+
+jobs:
+  build-linux:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: 13.x
+      - name: Environment Information
+        run: npx envinfo
+      - name: Build
+        run: ./configure && make -j2
+  build-windows:
+    runs-on: windows-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: 13.x
+      - name: Environment Information
+        run: npx envinfo
+      - name: Install deps
+        run: choco install nasm
+      - name: Build
+        run: ./vcbuild.bat
+  build-macOS:
+    runs-on: macOS-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v1
+        with:
+          node-version: 13.x
+      - name: Environment Information
+        run: npx envinfo
+      - name: Build
+        run: ./configure && make -j8