[Bug c++/24985] caret diagnostics

["jason at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=24985

--- Comment #31 from Jason Merrill <jason at gcc dot gnu.org> 2012-04-12 21:44:23 UTC ---
The effect of this patch on overload resolution diagnostics is problematic:

-----
void f();
void f(int,int);

int main()
{
  f(1);
}
-----

wa2.C: In function âint main()â:
wa2.C:6:6: error: no matching function for call to âf(int)â
   f(1);
      ^
wa2.C:6:6: note: candidates are:
   f(1);
      ^
wa2.C:1:6: note: void f()
 void f();
      ^
wa2.C:1:6: note:   candidate expects 0 arguments, 1 provided
 void f();
      ^
wa2.C:2:6: note: void f(int, int)
 void f(int,int);
      ^
wa2.C:2:6: note:   candidate expects 2 arguments, 1 provided
 void f(int,int);
      ^

When there are multiple diagnostics at the same input location, we should only
print the source/caret information once.