[clangd][clang-tidy][stdlib] Add a missing symbol to the mapping.

clang/lib/Tooling/Inclusions/Stdlib/StdSpecialSymbolMap.inc

 
 // cppreference symbol index page was missing these symbols.
 // Remove them when the cppreference offline archive catches up.
 SYMBOL(index_sequence, std::, <utility>)
 SYMBOL(index_sequence_for, std::, <utility>)
 SYMBOL(make_index_sequence, std::, <utility>)
 SYMBOL(make_integer_sequence, std::, <utility>)
 
+// Symbols missing from the generated symbol map as reported by users.
+// Remove when the generator starts producing them.
+SYMBOL(make_any, std::, <any>)
+
 // The std::placeholder symbols (_1, ..., _N) are listed in the cppreference
 // placeholder.html, but the index only contains a single entry with "_1, _2, ..., _N"
 // text, which are not handled by the script.
 // N is an implementation-defined number (10 for libc++; 29 for libstdc++).
 SYMBOL(_1, std::placeholders::, <functional>)
 SYMBOL(_2, std::placeholders::, <functional>)
 SYMBOL(_3, std::placeholders::, <functional>)
 SYMBOL(_4, std::placeholders::, <functional>)