Remove some #includes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119967 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCDwarf.cpp b/lib/MC/MCDwarf.cpp
index 67ce43d..adefa5d 100644
--- a/lib/MC/MCDwarf.cpp
+++ b/lib/MC/MCDwarf.cpp
@@ -9,6 +9,7 @@
 
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCAssembler.h"
+#include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCContext.h"