[llvm] [clang] [clang][DependencyScanner] Remove unused -ivfsoverlay files (PR #73734)

[Jan Svoboda via cfe-commits]

================
@@ -141,6 +141,22 @@ std::vector<bool> HeaderSearch::computeUserEntryUsage() const {
   return UserEntryUsage;
 }
 
+std::vector<bool> HeaderSearch::computeVFSUsageAndClear() const {
----------------
jansvoboda11 wrote:

Nit: I'm a bit confused that the function that actually does the work (the logic itself, constructing offset tables, piping relevant files into `FileManager`) is called `collectNonAffectingInputFiles()`, while this function (that just traverses the VFS tree and collects bits) is called `computeVFSUsageAndClear()`. I'd expect it to be the other way around.

https://github.com/llvm/llvm-project/pull/73734