[clang] [Clang] Fix handling of pack indexing types in constraints of redeclaration (PR #139057)

[Younan Zhang via cfe-commits]

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@@ -1476,8 +1478,8 @@ namespace {
       }
     }
 
-    TemplateArgument
-    getTemplateArgumentPackPatternForRewrite(const TemplateArgument &TA) {
+    TemplateArgument getTemplateArgumentorUnsubstitutedExpansionPattern(
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zyn0217 wrote:

```suggestion
    TemplateArgument getTemplateArgumentOrUnsubstitutedExpansionPattern(
```

https://github.com/llvm/llvm-project/pull/139057