[clang] [clang-tools-extra] [clang] Add a valid begin source location for abbreviated function templates (PR #174723)

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@@ -57,6 +57,67 @@ TEST(Hover, Structured) {
          HI.Type = "void ()";
          HI.Parameters.emplace();
        }},
+      {R"cpp(
+          // Best foo ever.
+          void [[fo^o]](auto x) {}
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tcottin wrote:

I added a test but I am not sure if this is what you had in mind.
Please have another look.

https://github.com/llvm/llvm-project/pull/174723