.github/workflow: Add an atomic align check

Closes #1661

.github/workflows/test.yml

@@ -67,6 +67,11 @@ jobs:
         run: |
           go vet -tags=example -v ./...
 
+      - name: go vet (atomic align)
+        run: |
+          go install .github/workflows/vettools/atomicalign.go
+          go vet -vettool=$(which atomicalign) -tags=example -v ./...
+
       - name: go build
         run: |
           go build -tags=example -v ./...

.github/workflows/vettools/atomicalign.go

@@ -0,0 +1,27 @@
+// Copyright 2021 The Ebiten Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build ignore
+// +build ignore
+
+package main
+
+import (
+	"golang.org/x/tools/go/analysis/multichecker"
+	"golang.org/x/tools/go/analysis/passes/atomicalign"
+)
+
+func main() {
+	multichecker.Main(atomicalign.Analyzer)
+}