I think there was some confusion about what I meant. :-) Replacing the comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137743 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Utils/SimplifyCFG.cpp

@@ -2266,7 +2266,10 @@ bool SimplifyCFGOpt::SimplifyUnreachable(UnreachableInst *UI) {
                  !isa<LandingPadInst>(BBI)) {
         break;
       }
-      // FIXME: Handling of LandingPadInst (landingpad) is suspicious.
+      // Note that deleting LandingPad's here is in fact okay, although it
+      // involves a bit of subtle reasoning. If this inst is a LandingPad,
+      // all the predecessors of this block will be the unwind edges of Invokes,
+      // and we can therefore guarantee this block will be erased.
     }
 
     // Delete this instruction (any uses are guaranteed to be dead)