cmFileLockResult: Remove expensive windows.h include

Source/cmFileLock.cxx

@@ -12,11 +12,7 @@
 cmFileLock::cmFileLock(cmFileLock&& other) noexcept
 {
   this->File = other.File;
-#if defined(_WIN32)
-  other.File = INVALID_HANDLE_VALUE;
-#else
-  other.File = -1;
-#endif
+  other.File = (decltype(other.File))-1;
   this->Filename = std::move(other.Filename);
 }
 
@@ -32,11 +28,7 @@ cmFileLock::~cmFileLock()
 cmFileLock& cmFileLock::operator=(cmFileLock&& other) noexcept
 {
   this->File = other.File;
-#if defined(_WIN32)
-  other.File = INVALID_HANDLE_VALUE;
-#else
-  other.File = -1;
-#endif
+  other.File = (decltype(other.File))-1;
   this->Filename = std::move(other.Filename);
 
   return *this;

Source/cmFileLockResult.cxx

@@ -5,6 +5,10 @@
 #include <cerrno>
 #include <cstring>
 
+#ifdef _WIN32
+#  include <Windows.h>
+#endif
+
 cmFileLockResult cmFileLockResult::MakeOk()
 {
   return { OK, 0 };

Source/cmFileLockResult.h

@@ -6,10 +6,6 @@
 
 #include <string>
 
-#if defined(_WIN32)
-#  include <windows.h> // DWORD
-#endif
-
 /**
  * @brief Result of the locking/unlocking file.
  * @note See @c cmFileLock
@@ -17,11 +13,7 @@
 class cmFileLockResult
 {
 public:
-#if defined(_WIN32)
-  using Error = DWORD;
-#else
   using Error = int;
-#endif
 
   /**
    * @brief Successful lock/unlock.