add a data() method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126590 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/ArrayRef.h

@@ -79,6 +79,8 @@ namespace llvm {
     /// empty - Check if the array is empty.
     bool empty() const { return Length == 0; }
     
+    const T *data() const { return Data; }
+    
     /// size - Get the array size.
     size_t size() const { return Length; }