Index: lib/Headers/arm64intr.h
===================================================================
--- lib/Headers/arm64intr.h
+++ lib/Headers/arm64intr.h
@@ -26,6 +26,10 @@
 #include_next <arm64intr.h>
 #else
 
+#if __STDC_HOSTED__
+#include <stdlib.h>
+#endif
+
 #ifndef __ARM64INTR_H
 #define __ARM64INTR_H