[Remarks] Fix usage of enum class

Breaks the build on some compilers:

http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/9720/steps/build%20stage%201/logs/stdio

llvm-svn: 362165
diff --git a/llvm/include/llvm/Remarks/RemarkSerializer.h b/llvm/include/llvm/Remarks/RemarkSerializer.h
index 7431ace..def5c2e 100644
--- a/llvm/include/llvm/Remarks/RemarkSerializer.h
+++ b/llvm/include/llvm/Remarks/RemarkSerializer.h
@@ -56,7 +56,7 @@
   yaml::Output YAMLOutput;
 
   YAMLSerializer(raw_ostream &OS,
-                 UseStringTable UseStringTable = UseStringTable::No);
+                 UseStringTable UseStringTable = remarks::UseStringTable::No);
 
   /// Emit a remark to the stream.
   void emit(const Remark &Remark) override;
diff --git a/llvm/lib/Remarks/YAMLRemarkSerializer.cpp b/llvm/lib/Remarks/YAMLRemarkSerializer.cpp
index 47fef5d..14de44f 100644
--- a/llvm/lib/Remarks/YAMLRemarkSerializer.cpp
+++ b/llvm/lib/Remarks/YAMLRemarkSerializer.cpp
@@ -154,7 +154,7 @@
 
 YAMLSerializer::YAMLSerializer(raw_ostream &OS, UseStringTable UseStringTable)
     : Serializer(OS), YAMLOutput(OS, reinterpret_cast<void *>(this)) {
-  if (UseStringTable == UseStringTable::Yes || RemarksYAMLStringTable)
+  if (UseStringTable == remarks::UseStringTable::Yes || RemarksYAMLStringTable)
     StrTab.emplace();
 }