[clang][Interp][NFC] Remove some redundant code

The needsRuntimeArgPop() stuff is now handled by the
cleanupAfterFunctionCall() function.

clang/lib/AST/Interp/Function.cpp

@@ -48,9 +48,3 @@ bool Function::isVirtual() const {
     return M->isVirtual();
   return false;
 }
-
-bool Function::needsRuntimeArgPop(const ASTContext &Ctx) const {
-  if (!isBuiltin())
-    return false;
-  return Ctx.BuiltinInfo.hasCustomTypechecking(getBuiltinID());
-}

clang/lib/AST/Interp/Function.h

@@ -179,10 +179,6 @@ class Function final {
 
   bool isBuiltin() const { return F->getBuiltinID() != 0; }
 
-  /// Does this function need its arguments to be classified at runtime
-  /// rather than at bytecode-compile-time?
-  bool needsRuntimeArgPop(const ASTContext &Ctx) const;
-
   unsigned getNumParams() const { return ParamTypes.size(); }
 
   unsigned getParamOffset(unsigned ParamIndex) const {

clang/lib/AST/Interp/Interp.cpp

@@ -131,20 +131,6 @@ void cleanupAfterFunctionCall(InterpState &S, CodePtr OpPC) {
   const Function *CurFunc = S.Current->getFunction();
   assert(CurFunc);
 
-  // Certain builtin functions are declared as func-name(...), so the
-  // parameters are checked in Sema and only available through the CallExpr.
-  // The interp::Function we create for them has 0 parameters, so we need to
-  // remove them from the stack by checking the CallExpr.
-  // FIXME: This is potentially just a special case and could be handled more
-  // generally with the code just below?
-  if (CurFunc->needsRuntimeArgPop(S.getCtx())) {
-    const auto *CE = cast<CallExpr>(S.Current->getExpr(OpPC));
-    for (int32_t I = CE->getNumArgs() - 1; I >= 0; --I) {
-      popArg(S, CE->getArg(I));
-    }
-    return;
-  }
-
   if (S.Current->Caller && CurFunc->isVariadic()) {
     // CallExpr we're look for is at the return PC of the current function, i.e.
     // in the caller.