[CI] Add support for GitHub Actions (#810)

Added licenses, formatted non-Swift source files, etc. Only
run tests on Linux, since the macOS CI build uses
the Xcode-bundled stdlib (or maybe the one in the OS), which
doesn't permit the SPI import that string-processing requires.

Author: shahmishal

.github/workflows/pull_request.yml

@@ -0,0 +1,21 @@
+name: Pull request
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize]
+
+jobs:
+  tests:
+    name: Test
+    uses: swiftlang/github-workflows/.github/workflows/swift_package_test.yml@main
+    with:
+      linux_exclude_swift_versions: '[{"swift_version": "5.9"}, {"swift_version": "5.10"}]'
+      enable_windows_checks: false
+      enable_macos_checks: false
+  soundness:
+    name: Soundness
+    uses: swiftlang/github-workflows/.github/workflows/soundness.yml@main
+    with:
+      license_header_check_project_name: "Swift.org"
+      unacceptable_language_check_enabled: false
+      format_check_enabled: false

.license_header_template

@@ -0,0 +1,10 @@
+@@===----------------------------------------------------------------------===@@
+@@
+@@ This source file is part of the Swift.org open source project
+@@
+@@ Copyright (c) YEARS Apple Inc. and the Swift project authors
+@@ Licensed under Apache License v2.0 with Runtime Library Exception
+@@
+@@ See https://swift.org/LICENSE.txt for license information
+@@
+@@===----------------------------------------------------------------------===@@

.licenseignore

@@ -0,0 +1,25 @@
+.gitignore
+**/.gitignore
+.licenseignore
+.gitattributes
+.git-blame-ignore-revs
+.mailfilter
+.mailmap
+.spi.yml
+.swift-format
+.editorconfig
+.github/*
+.build
+*.py
+*.yml
+*.yaml
+*.cmake
+*.cmake.in
+Package.swift
+**/Package.swift
+Package@*.swift
+**/Package@*.swift
+Package.resolved
+**/Package.resolved
+.unacceptablelanguageignore
+ -a*/Snapshots/*

Sources/RegexBenchmark/Benchmark.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 @_spi(RegexBenchmark) import _StringProcessing
 internal import _RegexParser
 import Foundation

Sources/RegexBenchmark/BenchmarkRegistration.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 // This file has lines generated by createBenchmark.py
 // Do not remove the start of registration or end of registration markers
 

Sources/RegexBenchmark/BenchmarkResults.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 import Foundation
 
 extension BenchmarkRunner {

Sources/RegexBenchmark/BenchmarkRunner.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 import Foundation
 @_spi(RegexBenchmark) import _StringProcessing
 

Sources/RegexBenchmark/CLI.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 import ArgumentParser
 
 @main

Sources/RegexBenchmark/Debug.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 import Foundation
 
 protocol Debug {

Sources/RegexBenchmark/Inputs/CSS.swift

@@ -1,3 +1,14 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2021-2022 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+//
+//===----------------------------------------------------------------------===//
+
 enum Inputs {}
 
 extension Inputs {