[LAA] Make MaxSafeDepDistBytes private in LoopAccessAnalysis

[michaelmaitland]

Summary

Any users of LoopAccessAnalysis should use MaxSafeVectorWidthInBits.

[michaelmaitland]

As discussed in D150706.

[fhahn]

LGTM, thanks!

llvm/include/llvm/Analysis/LoopAccessAnalysis.h

public:
   /// Return true if the block BB needs to be predicated in order for the loop
   /// to be vectorized.
   static bool blockNeedsPredication(BasicBlock *BB, Loop *TheLoop,
                                     DominatorTree *DT);
 
   /// Returns true if value \p V is loop invariant.
   bool isInvariant(Value *V) const;
 
-  uint64_t getMaxSafeDepDistBytes() const { return MaxSafeDepDistBytes; }
   unsigned getNumStores() const { return NumStores; }
   unsigned getNumLoads() const { return NumLoads;}
 
   /// The diagnostics report generated for the analysis.  E.g. why we
   /// couldn't analyze the loop.
   const OptimizationRemarkAnalysis *getReport() const { return Report.get(); }
 
   /// the Memory Dependence Checker which can determine the