Try to open the file before use data from stat.

Looks like on mingw we get bogus last modification times on directories.
Should fix the mingw bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186240 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-ar/llvm-ar.cpp b/tools/llvm-ar/llvm-ar.cpp
index 5f47654..7632b00 100644
--- a/tools/llvm-ar/llvm-ar.cpp
+++ b/tools/llvm-ar/llvm-ar.cpp
@@ -560,6 +560,9 @@
       sys::fs::file_status Status;
       failIfError(sys::fs::status(FileName, Status), FileName);
 
+      OwningPtr<MemoryBuffer> File;
+      failIfError(MemoryBuffer::getFile(FileName, File), FileName);
+
       uint64_t secondsSinceEpoch =
           Status.getLastModificationTime().toEpochTime();
       printWithSpacePadding(Out, secondsSinceEpoch, 12);
@@ -570,8 +573,6 @@
       printWithSpacePadding(Out, Status.getSize(), 10);
       Out << "`\n";
 
-      OwningPtr<MemoryBuffer> File;
-      failIfError(MemoryBuffer::getFile(FileName, File), FileName);
       Out << File->getBuffer();
     } else {
       object::Archive::child_iterator OldMember = I->getOld();