[Runtime][Windows] A couple of files need to include <windows.h>

We shouldn't include <windows.h> implicitly from .cpp files, but should
do it directly so that we know it's there.

Also, if we're including <windows.h>, do it at the top of the file.

rdar://90776105

Author: al45tair

lib/Threading/Win32.cpp

@@ -16,6 +16,10 @@
 
 #if SWIFT_THREADING_WIN32
 
+#define WIN32_LEAN_AND_MEAN
+#define NOMINMAX
+#include <windows.h>
+
 #include "swift/Threading/Errors.h"
 #include "swift/Threading/Impl/Win32.h"
 

stdlib/public/Concurrency/TaskPrivate.h

@@ -17,6 +17,13 @@
 #ifndef SWIFT_CONCURRENCY_TASKPRIVATE_H
 #define SWIFT_CONCURRENCY_TASKPRIVATE_H
 
+#if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
+#define VC_EXTRA_LEAN
+#define NOMINMAX
+#include <Windows.h>
+#endif
+
 #include "Error.h"
 #include "Tracing.h"
 #include "swift/ABI/Metadata.h"
@@ -36,12 +43,6 @@
 #if HAVE_PTHREAD_H
 #include <pthread.h>
 #endif
-#if defined(_WIN32)
-#define WIN32_LEAN_AND_MEAN
-#define VC_EXTRA_LEAN
-#define NOMINMAX
-#include <Windows.h>
-#endif
 
 namespace swift {
 

stdlib/public/runtime/Errors.cpp

@@ -15,6 +15,10 @@
 //===----------------------------------------------------------------------===//
 
 #if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
+#define NOMINMAX
+#include <windows.h>
+
 #include <mutex>
 #endif
 

stdlib/public/runtime/Metadata.cpp

@@ -14,6 +14,13 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
+// Avoid defining macro max(), min() which conflict with std::max(), std::min()
+#define NOMINMAX
+#include <windows.h>
+#endif
+
 #include "swift/Runtime/Metadata.h"
 #include "MetadataCache.h"
 #include "swift/Basic/Lazy.h"
@@ -37,12 +44,6 @@
 #include <new>
 #include <unordered_set>
 #include <vector>
-#if defined(_WIN32)
-#define WIN32_LEAN_AND_MEAN
-// Avoid defining macro max(), min() which conflict with std::max(), std::min()
-#define NOMINMAX
-#include <windows.h>
-#endif
 #if SWIFT_PTRAUTH
 #include <ptrauth.h>
 #endif