COFF: disambiguate make_unique (NFC)

This disambiguates `llvm::make_unqiue` and `std::make_unique` for the Windows
buildbots.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@280014 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/COFF/Writer.cpp b/COFF/Writer.cpp
index 64924aa..6c3a7bd 100644
--- a/COFF/Writer.cpp
+++ b/COFF/Writer.cpp
@@ -355,11 +355,11 @@
 
   // Create Debug Information Chunks
   if (Config->Debug) {
-    DebugDirectory = make_unique<DebugDirectoryChunk>(DebugRecords);
+    DebugDirectory = llvm::make_unique<DebugDirectoryChunk>(DebugRecords);
 
     // TODO(compnerd) create a coffgrp entry if DebugType::CV is not enabled
     if (Config->DebugTypes & static_cast<unsigned>(coff::DebugType::CV))
-      DebugRecords.push_back(make_unique<CVDebugRecordChunk>());
+      DebugRecords.push_back(llvm::make_unique<CVDebugRecordChunk>());
 
     RData->addChunk(DebugDirectory.get());
     for (const std::unique_ptr<Chunk> &C : DebugRecords)