[CallSite removal][CodeGen] Use CallBase instead of ImmutableCallSite in TargetFrameLoweringInfo. NFC

llvm/lib/CodeGen/TargetFrameLoweringImpl.cpp

@@ -18,9 +18,9 @@
 #include "llvm/CodeGen/TargetRegisterInfo.h"
 #include "llvm/CodeGen/TargetSubtargetInfo.h"
 #include "llvm/IR/Attributes.h"
-#include "llvm/IR/CallSite.h"
 #include "llvm/IR/CallingConv.h"
 #include "llvm/IR/Function.h"
+#include "llvm/IR/InstrTypes.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Target/TargetMachine.h"
@@ -141,8 +141,8 @@ bool TargetFrameLowering::isSafeForNoCSROpt(const Function &F) {
     return false;
   // Function should not be optimized as tail call.
   for (const User *U : F.users())
-    if (auto CS = ImmutableCallSite(U))
-      if (CS.isTailCall())
+    if (auto *CB = dyn_cast<CallBase>(U))
+      if (CB->isTailCall())
         return false;
   return true;
 }