Make aliasesPointer and aliasesUnknownInst public members of AliasSet.

These query functions are safe for external use and, furthermore,
are the only way to make queries against the "unknown instructions" array.
BBVectorize will use these functions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150248 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/AliasSetTracker.h

@@ -264,6 +264,7 @@ private:
   }
   void setVolatile() { Volatile = true; }
 
+public:
   /// aliasesPointer - Return true if the specified pointer "may" (or must)
   /// alias one of the members in the set.
   ///