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/Target/SubtargetFeature.cpp b/lib/Target/SubtargetFeature.cpp
index ba53d63..3cf95b5 100644
--- a/lib/Target/SubtargetFeature.cpp
+++ b/lib/Target/SubtargetFeature.cpp
@@ -18,6 +18,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cctype>
+#include <cstdlib>
 using namespace llvm;
 
 //===----------------------------------------------------------------------===//