[llvm][NFC][CallSite] Remove CallSite from Lint.cpp

[mtrofin]

Summary

The CallSite arg iterator is really User::op_iterator.

[craig.topper]

LGTM

llvm/lib/Analysis/Lint.cpp

 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/MemoryLocation.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Argument.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constant.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/Dominators.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/InstVisitor.h"
if (Function *F = dyn_cast<Function>(findValue(Callee,
     Assert(FT->getReturnType() == I.getType(),
            "Undefined behavior: Call return type mismatches "
            "callee return type",
            &I);
 
     // Check argument types (in case the callee was casted) and attributes.
     // TODO: Verify that caller and callee attributes are compatible.
     Function::arg_iterator PI = F->arg_begin(), PE = F->arg_end();
-    CallSite::arg_iterator AI = I.arg_begin(), AE = I.arg_end();
+    auto AI = I.arg_begin(), AE = I.arg_end();
     for (; AI != AE; ++AI) {
       Value *Actual = *AI;
       if (PI != PE) {
         Argument *Formal = &*PI++;
         Assert(Formal->getType() == Actual->getType(),
                "Undefined behavior: Call argument type mismatches "
                "callee parameter type",
                &I);
 
         // Check that noalias arguments don't alias other arguments. This is
         // not fully precise because we don't know the sizes of the dereferenced
         // memory regions.
         if (Formal->hasNoAliasAttr() && Actual->getType()->isPointerTy()) {
           AttributeList PAL = I.getAttributes();
           unsigned ArgNo = 0;
-          for (CallSite::arg_iterator BI = I.arg_begin(); BI != AE;
-               ++BI, ++ArgNo) {
+          for (auto BI = I.arg_begin(); BI != AE; ++BI, ++ArgNo) {
             // Skip ByVal arguments since they will be memcpy'd to the callee's
             // stack so we're not really passing the pointer anyway.
             if (PAL.hasParamAttribute(ArgNo, Attribute::ByVal))
               continue;
             // If both arguments are readonly, they have no dependence.
             if (Formal->onlyReadsMemory() && I.onlyReadsMemory(ArgNo))
               continue;
             if (AI != BI && (*BI)->getType()->isPointerTy()) {