Add missing include (for r205050)

llvm-svn: 205053

llvm/tools/llvm-mc/llvm-mc.cpp

@@ -26,6 +26,7 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compression.h"
 #include "llvm/Support/FileUtilities.h"
 #include "llvm/Support/FormattedStream.h"
 #include "llvm/Support/Host.h"