Revert r296215, "[PDB] General improvements to Stream library." and followings.

r296215, "[PDB] General improvements to Stream library."
r296217, "Disable BinaryStreamTest.StreamReaderObject temporarily."
r296220, "Re-enable BinaryStreamTest.StreamReaderObject."
r296244, "[PDB] Disable some tests that are breaking bots."
r296249, "Add static_cast to silence -Wc++11-narrowing."

std::errc::no_buffer_space should be used for OS-oriented errors for socket transmission.
(Seek discussions around llvm/xray.)

I could substitute s/no_buffer_space/others/g, but I revert whole them ATM.

Could we define and use LLVM errors there?

llvm-svn: 296258
diff --git a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
index dff5334..4c85825 100644
--- a/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/NativeSession.cpp
@@ -45,8 +45,7 @@
     return make_error<GenericError>(generic_error_code::invalid_path);
 
   std::unique_ptr<MemoryBuffer> Buffer = std::move(*ErrorOrBuffer);
-  auto Stream = llvm::make_unique<MemoryBufferByteStream>(
-      std::move(Buffer), llvm::support::little);
+  auto Stream = llvm::make_unique<MemoryBufferByteStream>(std::move(Buffer));
 
   auto Allocator = llvm::make_unique<BumpPtrAllocator>();
   auto File = llvm::make_unique<PDBFile>(Path, std::move(Stream), *Allocator);