Silence warning about unused private variable.

llvm-svn: 325275
diff --git a/llvm/lib/Support/Unix/Path.inc b/llvm/lib/Support/Unix/Path.inc
index 220162d..088774a 100644
--- a/llvm/lib/Support/Unix/Path.inc
+++ b/llvm/lib/Support/Unix/Path.inc
@@ -643,7 +643,9 @@
 
 mapped_file_region::mapped_file_region(int fd, mapmode mode, size_t length,
                                        uint64_t offset, std::error_code &ec)
-    : Size(length), Mapping() {
+    : Size(length), Mapping(), FD(fd), Mode(mode) {
+  (void)FD;
+  (void)Mode;
   ec = init(fd, offset, mode);
   if (ec)
     Mapping = nullptr;