rt: Add libunwind.h support on Mac OS X

src/rt/rust_unwind.h

@@ -0,0 +1,21 @@
+// Unwinding stuff missing on some architectures (Mac OS X).
+
+#ifndef RUST_UNWIND_H
+#define RUST_UNWIND_H
+
+#ifdef __APPLE__
+#include <libunwind.h>
+
+typedef int _Unwind_Action;
+typedef void _Unwind_Context;
+typedef void _Unwind_Exception;
+typedef int _Unwind_Reason_Code;
+
+#else
+
+#include <unwind.h>
+
+#endif
+
+#endif
+

src/rt/rust_upcall.cpp

@@ -1,8 +1,8 @@
 #include "rust_gc.h"
 #include "rust_internal.h"
+#include "rust_unwind.h"
 #include "rust_upcall.h"
 #include <stdint.h>
-#include <unwind.h>
 
 // Upcalls.