Fix ambiguous use of overloaded symbols

Some constants are exported by CoreFoundation, but they has mismatched
type with WinSDK overlay.  Set them explicitly.

Author: stevapple

Sources/Foundation/FileHandle.swift

@@ -25,10 +25,10 @@ fileprivate let _close = Glibc.close(_:)
 #endif
 
 #if canImport(WinSDK)
-// We used to get the copy that was re-exported by CoreFoundation
+// We used to get the alias that was re-exported by CoreFoundation
 // but we want to explicitly depend on its types in this file,
 // so we need to make sure Swift doesn't think it's @_implementationOnly.
-import WinSDK
+import struct WinSDK.HANDLE
 #endif
 
 extension NSError {

Sources/Foundation/Process.swift

@@ -14,10 +14,10 @@ import Darwin
 #endif
 
 #if canImport(WinSDK)
-// We used to get the copy that was re-exported by CoreFoundation
+// We used to get the alias that was re-exported by CoreFoundation
 // but we want to explicitly depend on its types in this file,
 // so we need to make sure Swift doesn't think it's @_implementationOnly.
-import WinSDK
+import struct WinSDK.HANDLE
 #endif
 
 extension Process {
@@ -1162,6 +1162,13 @@ open class Process: NSObject {
 }
 
 extension Process {
-    
     public static let didTerminateNotification = NSNotification.Name(rawValue: "NSTaskDidTerminateNotification")
 }
+
+#if os(Windows)
+// FIXME: This is a workaround for CoreFoundation/WinSDK overload
+// of the same constants with different types.  We should prevent
+// CoreFoundation from re-exporting them.
+fileprivate let HANDLE_FLAG_INHERIT = DWORD(0x00000001)
+fileprivate let STARTF_USESTDHANDLES = DWORD(0x00000100)
+#endif