Update the code ownership.

llvm-svn: 168102
diff --git a/llvm/CODE_OWNERS.TXT b/llvm/CODE_OWNERS.TXT
index f94a9b3..c932be4 100644
--- a/llvm/CODE_OWNERS.TXT
+++ b/llvm/CODE_OWNERS.TXT
@@ -80,7 +80,7 @@
 
 N: Nadav Rotem
 E: nrotem@apple.com
-D: Loop Vectorizer
+D: X86 Backend, Loop Vectorizer
 
 N: Duncan Sands
 E: baldrick@free.fr