[clang] [clang-tools-extra] Remove `StringLiteral` in favor of `StringRef` (PR #122366)

[via cfe-commits]

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@@ -57,7 +57,7 @@ class DeclarationFragments {
     Keyword,
     Attribute,
     NumberLiteral,
-    StringLiteral,
+    StringRef,
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QuietMisdreavus wrote:

This is an unnecessary find-and-replace. This enum constant specifically references a string literal, not the `StringLiteral` type.

https://github.com/llvm/llvm-project/pull/122366