[Bug c++/86568] -Wnonnull warnings should highlight the relevant argument not the closing parenthesis

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86568

--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> ---
PR 95892 points out the -Wsign-conversion warnings below all have the location
of the closing parenthesis:

unsigned int var = 10;
void foo ( 
    int a = var, 
    int b = var,
    int c = var )   
{    }