[Assignment Tracking] Fix faulty assertion inside std::sort predicate

[Orlando]

Summary

The vectors being sorted here shouldn't contain duplicate entries. Prior to this patch this was checked with an assert within the std::sort predicate. However, std::sort may compare an element against itself which causes the assert to fire (false positive). Move the assert outside of the sort predicate to avoid such issues.

llvm/lib/CodeGen/AssignmentTrackingAnalysis.cpp

for (auto &I : BB) {
 
           if (Seen.insert(DV).second)
             FragmentMap[DA].push_back(DV);
         }
       }
     }
   }
 
-  // Sort the fragment map for each DebugAggregate in non-descending
-  // order of fragment size. Assert no entries are duplicates.
+  // Sort the fragment map for each DebugAggregate in ascending
+  // order of fragment size - there should be no duplicates.
   for (auto &Pair : FragmentMap) {
     SmallVector<DebugVariable, 8> &Frags = Pair.second;
-    std::sort(
-        Frags.begin(), Frags.end(), [](DebugVariable Next, DebugVariable Elmt) {
-          assert(!(Elmt.getFragmentOrDefault() == Next.getFragmentOrDefault()));
+    std::sort(Frags.begin(), Frags.end(),
+              [](const DebugVariable &Next, const DebugVariable &Elmt) {
                 return Elmt.getFragmentOrDefault().SizeInBits >
                        Next.getFragmentOrDefault().SizeInBits;
               });
+    // Check for duplicates.
+    assert(std::adjacent_find(Frags.begin(), Frags.end()) == Frags.end());
   }
 
   // Build the map.
   AssignmentTrackingLowering::OverlapMap Map;
   for (auto &Pair : FragmentMap) {
     auto &Frags = Pair.second;
     for (auto It = Frags.begin(), IEnd = Frags.end(); It != IEnd; ++It) {
       DIExpression::FragmentInfo Frag = It->getFragmentOrDefault();