TestFoundation: disable a couple of FileManager tests on Win32

The FileManager implementation currently does not provide some
attributes.  Disable the tests on Windows.

Author: compnerd

TestFoundation/TestFileManager.swift

@@ -367,15 +367,18 @@ class TestFileManager : XCTestCase {
             let systemSize = attrs[.systemSize] as? NSNumber
             XCTAssertNotNil(systemSize)
             XCTAssertGreaterThan(systemSize!.uint64Value, systemFreeSize!.uint64Value)
-            
+
+#if !os(Windows)
             let systemFreeNodes = attrs[.systemFreeNodes] as? NSNumber
             XCTAssertNotNil(systemFreeNodes)
             XCTAssertNotEqual(systemFreeNodes!.uint64Value, 0)
-            
+#endif
+
+#if !os(Windows)
             let systemNodes = attrs[.systemNodes] as? NSNumber
             XCTAssertNotNil(systemNodes)
             XCTAssertGreaterThan(systemNodes!.uint64Value, systemFreeNodes!.uint64Value)
-            
+#endif
         } catch {
             XCTFail("\(error)")
         }