[clang] [clang] Allow pack expansions when partial ordering against template template parameters (PR #91833)

[via cfe-commits]

================
@@ -9216,14 +9216,20 @@ class Sema final : public SemaBase {
   /// receive true if the cause for the error is the associated constraints of
   /// the template not being satisfied by the template arguments.
   ///
+  /// \param PartialOrderTTP If true, assume these template arguments are
+  /// the injected template arguments for a template template parameter.
+  /// This will relax the requirement that all it's possible uses are valid.
----------------
cor3ntin wrote:

```suggestion
  /// This will relax the requirement that all its possible uses are valid:
```

https://github.com/llvm/llvm-project/pull/91833