Add missing standard headers. Patch by Joerg Sonnenberger!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122193 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/AsmLexer.cpp b/lib/MC/MCParser/AsmLexer.cpp
index 085d519..e474a15 100644
--- a/lib/MC/MCParser/AsmLexer.cpp
+++ b/lib/MC/MCParser/AsmLexer.cpp
@@ -15,6 +15,7 @@
 #include "llvm/Support/SMLoc.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/MC/MCAsmInfo.h"
+#include <cctype>
 #include <cerrno>
 #include <cstdio>
 #include <cstdlib>