[clangd] Make go-to-def jumps to overriden methods on `final` specifier.

[merge_guards_bot]

Unit tests: pass. 62305 tests passed, 0 failed and 838 were skipped.

clang-tidy: pass.

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

clang-tools-extra/clangd/XRefs.cpp

 #include "SourceCode.h"
 #include "URI.h"
 #include "index/Index.h"
 #include "index/Merge.h"
 #include "index/Relation.h"
 #include "index/SymbolLocation.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Attr.h"
+#include "clang/AST/Attrs.inc"
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
std::vector<LocatedSymbol> locateSymbolAt(ParsedAST &AST, Position Pos,
   };
 
   // Emit all symbol locations (declaration or definition) from AST.
   DeclRelationSet Relations =
       DeclRelation::TemplatePattern | DeclRelation::Alias;
   for (const NamedDecl *D : getDeclAtPosition(AST, SourceLoc, Relations)) {
     // Special case: void foo() ^override: jump to the overridden method.
     if (const auto *CMD = llvm::dyn_cast<CXXMethodDecl>(D)) {
-      const auto *Attr = D->getAttr<OverrideAttr>();
+      const InheritableAttr* Attr = D->getAttr<OverrideAttr>();
+      if (!Attr)
+        Attr = D->getAttr<FinalAttr>();
       const syntax::Token *Tok =
           spelledIdentifierTouching(SourceLoc, AST.getTokens());
       if (Attr && Tok &&
           SM.getSpellingLoc(Attr->getLocation()) == Tok->location()) {
         // We may be overridding multiple methods - offer them all.
         for (const NamedDecl *ND : CMD->overridden_methods())
           AddResultDecl(ND);
         continue;

clang-tools-extra/clangd/unittests/XRefsTests.cpp

const char *Tests[] = {
         struct Fo^o<T*> {};
       )cpp",
 
       R"cpp(// Override specifier jumps to overridden method
         class Y { virtual void $decl[[a]]() = 0; };
         class X : Y { void a() ^override {} };
       )cpp",
 
+      R"cpp(// Final specifier jumps to overridden method
+        class Y { virtual void $decl[[a]]() = 0; };
+        class X : Y { void a() ^final {} };
+      )cpp",
+
       R"cpp(// Heuristic resolution of dependent method
         template <typename T>
         struct S {
           void [[bar]]() {}
         };
 
         template <typename T>
         void foo(S<T> arg) {