Update comment to be more accurate

Author: ilovepi

clang/lib/CodeGen/CGCall.cpp

@@ -4963,12 +4963,10 @@ void CodeGenFunction::EmitCallArg(CallArgList &args, const Expr *E,
 
   AggValueSlot ArgSlot = AggValueSlot::ignored();
   // For arguments with aggregate type, create an alloca to store
-  // the value.  If the argument's type has a destructor, that destructor
+  // the value. If the argument's type has a destructor, that destructor
   // will run at the end of the full-expression; emit matching lifetime
-  // markers.
-  //
-  // FIXME: For types which don't have a destructor, consider using a
-  // narrower lifetime bound.
+  // markers. For types which don't have a destructor, we use a narrower
+  // lifetime bound.
   if (hasAggregateEvaluationKind(E->getType())) {
     RawAddress ArgSlotAlloca = Address::invalid();
     ArgSlot = CreateAggTemp(E->getType(), "agg.tmp", &ArgSlotAlloca);