Add name offset flags, for parity with cvtres.exe.

Summary:
The original cvtres.exe sets the high bit when an identifier offset
points to a string.  Even though this is not mentioned in the spec, and
in fact does not seem to cause errors with most cases, for some reason
this causes a failure in Chromium where the new resource file is not
verified as a new version.  This patch sets this high bit flag, and also
adds a test case to check that the output of our library is always
identical to original cvtres.

Reviewers: zturner, ruiu

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D35099

llvm-svn: 307452

llvm/lib/Object/WindowsResource.cpp

@@ -616,8 +616,8 @@ void WindowsResourceCOFFWriter::writeDirectoryTree() {
     for (auto const &Child : StringChildren) {
       auto *Entry = reinterpret_cast<coff_resource_dir_entry *>(BufferStart +
                                                                 CurrentOffset);
-      Entry->Identifier.NameOffset =
-          StringTableOffsets[Child.second->getStringIndex()];
+      Entry->Identifier.setNameOffset(
+          StringTableOffsets[Child.second->getStringIndex()]);
       if (Child.second->checkIsDataNode()) {
         Entry->Offset.DataEntryOffset = NextLevelOffset;
         NextLevelOffset += sizeof(coff_resource_data_entry);