[clang-tools-extra] Implemented recursive search for findImplementations (PR #177564)

[via cfe-commits]

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@@ -1923,6 +1923,42 @@ TEST(FindImplementations, Inheritance) {
   }
 }
 
+TEST(FindImplementations, InheritanceRecursion) {
+  // Make sure inheritance is followed, but does not diverge.
+  llvm::StringRef Test = R"cpp(
+    template <int>
+    struct [[Ev^en]];
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timon-ul wrote:

Implemented this, but not sure if the expected behaviour of `defRange` when no definition is available is correct, failure vs. fallback on decl. Just decided to mirror the LSP request that falls back, but can understand if we do not want fallbacks.

https://github.com/llvm/llvm-project/pull/177564