Revert r283690, "MC: Remove unused entities."

llvm-svn: 283814
diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index 11c548a..124a191 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -72,6 +72,7 @@
 void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
 
 void MCStreamer::addExplicitComment(const Twine &T) {}
+void MCStreamer::emitExplicitComments() {}
 
 void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
   for (auto &FI : DwarfFrameInfos)
@@ -712,6 +713,9 @@
   EmitRawTextImpl(T.toStringRef(Str));
 }
 
+void MCStreamer::EmitWindowsUnwindTables() {
+}
+
 void MCStreamer::Finish() {
   if (!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End)
     report_fatal_error("Unfinished frame!");