Subzero: Clean up a few areas.

src/IceDefs.h

Index: src/IceDefs.h
diff --git a/src/IceDefs.h b/src/IceDefs.h
index 8aafbfd6c44a5502829f9fc0fd40a0d92e40ba4e..f5147c668c5afc86c99dfc8e8f576567a807db8f 100644
--- a/src/IceDefs.h
+++ b/src/IceDefs.h
@@ -29,6 +29,7 @@
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/ilist.h"
 #include "llvm/ADT/ilist_node.h"
+#include "llvm/ADT/iterator_range.h"
 #include "llvm/ADT/SmallBitVector.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
@@ -157,6 +158,17 @@ typedef uint32_t VerboseMask;
 typedef llvm::raw_ostream Ostream;
 typedef llvm::raw_fd_ostream Fdstream;
 
+// Reverse range adaptors written in terms of llvm::make_range().
+template <typename T>
+llvm::iterator_range<typename T::const_reverse_iterator>
+reverse_range(const T &Container) {
+  return llvm::make_range(Container.rbegin(), Container.rend());
+}
+template <typename T>
+llvm::iterator_range<typename T::reverse_iterator> reverse_range(T &Container) {
+  return llvm::make_range(Container.rbegin(), Container.rend());
+}
+
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H