[Attributor][NFC] Modify isAssumedHeapToStack for const argument

[ggeorgakoudis]

Summary

There is no need for a non-const argument interface and the const argument modification covers existing and upcoming use cases.

[jdoerfert]

LG, but replace the old one, no need to have a non-const version.

[ggeorgakoudis]

Fix for comments

[ggeorgakoudis]

Rebase

llvm/include/llvm/Transforms/IPO/Attributor.h

private:
   friend struct Attributor;
 };
 
 struct AAHeapToStack : public StateWrapper<BooleanState, AbstractAttribute> {
   using Base = StateWrapper<BooleanState, AbstractAttribute>;
   AAHeapToStack(const IRPosition &IRP, Attributor &A) : Base(IRP) {}
 
   /// Returns true if HeapToStack conversion is assumed to be possible.
-  virtual bool isAssumedHeapToStack(CallBase &CB) const = 0;
+  virtual bool isAssumedHeapToStack(const CallBase &CB) const = 0;
 
   /// Create an abstract attribute view for the position \p IRP.
   static AAHeapToStack &createForPosition(const IRPosition &IRP, Attributor &A);
 
   /// See AbstractAttribute::getName()
   const std::string getName() const override { return "AAHeapToStack"; }
 
   /// See AbstractAttribute::getIdAddr()

llvm/lib/Transforms/IPO/AttributorAttributes.cpp

void trackStatistics() const override {
     STATS_DECL(
         MallocCalls, Function,
         "Number of malloc/calloc/aligned_alloc calls converted to allocas");
     for (auto &It : AllocationInfos)
       if (It.second->Status != AllocationInfo::INVALID)
         ++BUILD_STAT_NAME(MallocCalls, Function);
   }
 
-  bool isAssumedHeapToStack(CallBase &CB) const override {
+  bool isAssumedHeapToStack(const CallBase &CB) const override {
     if (isValidState())
       if (AllocationInfo *AI = AllocationInfos.lookup(&CB))
         return AI->Status != AllocationInfo::INVALID;
     return false;
   }
 
   ChangeStatus manifest(Attributor &A) override {
     assert(getState().isValidState() &&