[Tooling/Inclusion] Add missing index_sequence symbols.

[hokein]

Summary

Fixes https://github.com/llvm/llvm-project/issues/61026

[hokein]

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

251

I have updated the cppreference symbol page, now it has entries for these four symbols.

[kadircet]

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

252

there's also integer_sequence see https://eel.is/c++draft/utility.syn

[hokein]

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

252

The integer_sequence has been indexed in the symbol page, it is already in StdSymbolMap.inc, https://github.com/llvm/llvm-project/blob/main/clang/lib/Tooling/Inclusions/Stdlib/StdSymbolMap.inc#L1576

[kadircet]

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

252

oops, thanks!

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

 SYMBOL(abs, None, <cmath>)
 SYMBOL(abs, None, <math.h>)
 
 // std::get has a few variants for different types (tuple, array, pair etc)
 // which is tricky to disambiguate without type information.
 // Don't set any header for it, as it comes with the type header.
 SYMBOL(get, std::, /*no headers*/)
 
+// 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>)
+
 // Macros
 SYMBOL(NULL, None, <cstddef>)
 SYMBOL(NULL, None, <stddef.h>)
 SYMBOL(NULL, None, <cstdlib>)
 SYMBOL(NULL, None, <stdlib.h>)
 SYMBOL(NULL, None, <cstring>)
 SYMBOL(NULL, None, <string.h>)
 SYMBOL(NULL, None, <cwchar>)
 SYMBOL(NULL, None, <wchar.h>)
 SYMBOL(NULL, None, <ctime>)
 SYMBOL(NULL, None, <time.h>)
 SYMBOL(NULL, None, <clocale>)
 SYMBOL(NULL, None, <locale.h>)
 SYMBOL(NULL, None, <cstdio>)
 SYMBOL(NULL, None, <stdio.h>)