[clang-doc] Fix segfault in comment sorting

clang-tools-extra/clang-doc/Representation.h

struct CommentInfo {
   bool operator<(const CommentInfo &Other) const {
     auto FirstCI = std::tie(Kind, Text, Name, Direction, ParamName, CloseName,
                             SelfClosing, Explicit, AttrKeys, AttrValues, Args);
     auto SecondCI =
         std::tie(Other.Kind, Other.Text, Other.Name, Other.Direction,
                  Other.ParamName, Other.CloseName, Other.SelfClosing,
                  Other.Explicit, Other.AttrKeys, Other.AttrValues, Other.Args);
 
-    if (FirstCI < SecondCI ||
-        (FirstCI == SecondCI && Children.size() < Other.Children.size()))
+    if (FirstCI < SecondCI)
       return true;
 
-    if (FirstCI > SecondCI || Children.size() > Other.Children.size())
-      return false;
+    if (FirstCI == SecondCI) {
+      return std::lexicographical_compare(
+          Children.begin(), Children.end(), Other.Children.begin(),
+          Other.Children.end(), llvm::deref<llvm::less>());
+    }
 
-    return std::equal(Children.begin(), Children.end(), Other.Children.begin(),
-                      llvm::deref<llvm::less>{});
+    return false;
   }
 
   SmallString<16>
       Kind; // Kind of comment (FullComment, ParagraphComment, TextComment,
             // InlineCommandComment, HTMLStartTagComment, HTMLEndTagComment,
             // BlockCommandComment, ParamCommandComment,
             // TParamCommandComment, VerbatimBlockComment,
             // VerbatimBlockLineComment, VerbatimLineComment).