[CK-TILE] Guard against compiler lexer diagnostic (#3444)

* [CK-TILE] Guard against compiler lexer diagnostic

A recent change to Clang added a lexer-level diagnostic about that C2y
language feature. Since that is lexer level, the `__extension__`
compiler built-in does not work as it is only respected *after* the
lexer when parsing.

This change adds guarding pragmas to disable the diagnostic in the
lexer and not lead to warnings being treated as errors.

* Fixing still existing build issue

Once the one warning was removed, another one poppoed up. Both are
related to the same c2y feature. Thus, ignoring both.

* clang-format handling

---------

Co-authored-by: Illia Silin <98187287+illsilin@users.noreply.github.com>