[llvm][NFC][CallSite] Remove Implementation uses of CallSite

Reviewers: dblaikie, davidxl, craig.topper

Subscribers: arsenm, dschuff, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78142

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -27,7 +27,6 @@
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/AutoUpgrade.h"
 #include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Comdat.h"
 #include "llvm/IR/Constant.h"
@@ -5312,7 +5311,7 @@ Error BitcodeReader::materialize(GlobalValue *GV) {
     for (auto UI = I.first->materialized_user_begin(), UE = I.first->user_end();
          UI != UE;)
       // Don't expect any other users than call sites
-      CallSite(*UI++).setCalledFunction(I.second);
+      cast<CallBase>(*UI++)->setCalledFunction(I.second);
 
   // Finish fn->subprogram upgrade for materialized functions.
   if (DISubprogram *SP = MDLoader->lookupSubprogramForFunction(F))