[clang] [InstallAPI] Pick up input headers by directory traversal (PR #94508)

[Cyndy Ishida via cfe-commits]

================
@@ -97,6 +97,14 @@ class HeaderFile {
                                           Other.Excluded, Other.Extra,
                                           Other.Umbrella);
   }
+
+  bool operator<(const HeaderFile &Other) const {
----------------
cyndyishida wrote:

I could infer, but I don't actually know @ributzka do you remember?

https://github.com/llvm/llvm-project/pull/94508