[Bug c++/95892] Wrong line number in "-Wsign-conversion" warning message

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95892

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This is a well-known issue where diagnostics in function parameter-lists all
have the location of the closing brace.