[LAA] Make blockNeedsPredication arguments const (NFC).

The arguments aren't modified, mark them as const. This prepares for new
users in a follow-up, which only have access to const versions of the
arguments.

Author: fhahn

llvm/include/llvm/Analysis/LoopAccessAnalysis.h

@@ -724,8 +724,9 @@ class LoopAccessInfo {
 
   /// Return true if the block BB needs to be predicated in order for the loop
   /// to be vectorized.
-  LLVM_ABI static bool blockNeedsPredication(BasicBlock *BB, Loop *TheLoop,
-                                             DominatorTree *DT);
+  LLVM_ABI static bool blockNeedsPredication(const BasicBlock *BB,
+                                             const Loop *TheLoop,
+                                             const DominatorTree *DT);
 
   /// Returns true if value \p V is loop invariant.
   LLVM_ABI bool isInvariant(Value *V) const;

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -2856,8 +2856,9 @@ void LoopAccessInfo::emitUnsafeDependenceRemark() {
   }
 }
 
-bool LoopAccessInfo::blockNeedsPredication(BasicBlock *BB, Loop *TheLoop,
-                                           DominatorTree *DT)  {
+bool LoopAccessInfo::blockNeedsPredication(const BasicBlock *BB,
+                                           const Loop *TheLoop,
+                                           const DominatorTree *DT) {
   assert(TheLoop->contains(BB) && "Unknown block used");
 
   // Blocks that do not dominate the latch need predication.