llvm-mc: Implement .abort fully in the front end


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77272 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/tools/llvm-mc/MC-X86Specific.cpp b/tools/llvm-mc/MC-X86Specific.cpp
index d16bb15..6e28b02 100644
--- a/tools/llvm-mc/MC-X86Specific.cpp
+++ b/tools/llvm-mc/MC-X86Specific.cpp
@@ -13,6 +13,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "AsmParser.h"
+#include "llvm/ADT/Twine.h"
 #include "llvm/MC/MCInst.h"
 #include "llvm/Support/SourceMgr.h"
 using namespace llvm;