[clang] [clang-tools-extra] [clangd] Fix crash with null check for Token at Loc (PR #94528)

[Utkarsh Saxena via cfe-commits]

================
@@ -1354,6 +1354,8 @@ maybeFindIncludeReferences(ParsedAST &AST, Position Pos,
 
         ReferencesResult::Reference Result;
         const auto *Token = AST.getTokens().spelledTokenAt(Loc);
+        if (!Token)
----------------
usx95 wrote:

Done.
> also, what's the conclusion of investigation around don't really rely on spelledTokenAt failing when it's called with a random offset into the token?

I relied on the tests here. Also, the usages of `spelledTokenCotaining` does not seem to relying on getting a `nullptr` if the location is inside a token, as compared to strictly at the beginning of tok.

https://github.com/llvm/llvm-project/pull/94528