Added two missing headers from ObjCARCAliasAnalysis.h.

This was missed since whenever I was including ObjCARCAliasAnalysis.h, I
was including ObjCARC.h before it which included these includes
(resulting in no compilation breakage).

llvm-svn: 173764

llvm/lib/Transforms/ObjCARC/ObjCARCAliasAnalysis.h

@@ -23,6 +23,9 @@
 #ifndef LLVM_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
 #define LLVM_TRANSFORMS_OBJCARC_OBJCARCALIASANALYSIS_H
 
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Pass.h"
+
 namespace llvm {
 namespace objcarc {