[clang] [clang][index][USR] GenLoc prints file entry at most once, allow repeated offsets (PR #205430)

[Balázs Benics via cfe-commits]

================
@@ -636,23 +656,28 @@ void USRGenerator::GenExtSymbolContainer(const NamedDecl *D) {
 }
 
 bool USRGenerator::GenLoc(const Decl *D, bool IncludeOffset) {
-  if (generatedLoc)
-    return IgnoreResults;
-  generatedLoc = true;
-
   // Guard against null declarations in invalid code.
   if (!D) {
     IgnoreResults = true;
     return true;
   }
+  // Do nothing if file entry has been printed and no need to print the offset.
+  if (GeneratedFileEntry && !IncludeOffset)
----------------
steakhal wrote:

For me, it would make more sense to swap the order of these conditions.
For example, I'd read this as:
if we didn't ask for offsets, then well, we are done.
Otherwise, if we have already generated then we don't need to print again.

https://github.com/llvm/llvm-project/pull/205430