swiftlint: add a Windows port

This enables building the swiftlint command on Windows.  There is no
system ioctl for terminal access, instead, we can use the Win32 Console
API surface to query the console size.  In the case of a failure, assume
the width to be 80-columns (as the standard VGA console is 80x25).

Author: compnerd

Source/SwiftLintFramework/Configuration+CommandLine.swift

@@ -69,7 +69,7 @@ private func fileCount(from envVar: String) throws(SwiftLintError) -> Int {
     return count
 }
 
-#if os(Linux)
+#if os(Linux) || os(Windows)
 private func autoreleasepool<T>(block: () -> T) -> T { block() }
 #endif
 

Source/SwiftLintFramework/LintOrAnalyzeCommand.swift

@@ -444,7 +444,7 @@ private actor CorrectionsBuilder {
 }
 
 private func memoryUsage() -> String? {
-#if os(Linux)
+#if os(Linux) || os(Windows)
     return nil
 #else
     var info = mach_task_basic_info()

Source/SwiftLintFramework/ProgressBar.swift

@@ -52,7 +52,7 @@ actor ProgressBar {
     }
 }
 
-#if os(Linux)
+#if os(Linux) || os(Windows)
 // swiftlint:disable:next identifier_name
 private let NSEC_PER_SEC = 1_000_000_000
 #endif

Source/swiftlint/Commands/Rules.swift

@@ -2,6 +2,9 @@ import ArgumentParser
 import Foundation
 import SwiftLintFramework
 import SwiftyTextTable
+#if os(Windows)
+import WinSDK
+#endif
 
 private typealias SortedRules = [(String, any Rule.Type)]
 
@@ -141,12 +144,20 @@ private extension TextTable {
 
 private struct Terminal {
     static func currentWidth() -> Int {
+#if os(Windows)
+        var csbi = CONSOLE_SCREEN_BUFFER_INFO()
+        guard GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi) else {
+            return 80
+        }
+        return Int(csbi.srWindow.Right - csbi.srWindow.Left) + 1
+#else
         var size = winsize()
 #if os(Linux)
         _ = ioctl(CInt(STDOUT_FILENO), UInt(TIOCGWINSZ), &size)
 #else
         _ = ioctl(STDOUT_FILENO, TIOCGWINSZ, &size)
 #endif
         return Int(size.ws_col)
+#endif
     }
 }