add #include

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@32281 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Target/Alpha/AlphaAsmPrinter.cpp

@@ -21,6 +21,7 @@
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/Target/TargetAsmInfo.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/Mangler.h"
 #include "llvm/ADT/Statistic.h"
 #include <iostream>