[Bug c/66527] incorrect line number in diagnostics for multiline initializers

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66527

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
Here's a slightly different test case showing a similar problem and pointing
out that the issue isn't specific to initializers.  Also, the warning at the
end is incorrect (probably the fallout from the prior errors).

int foo (register int a, register int b)
{
    return
    *
    (
    a
    ?
    &
    a
    :
    &
    b
    );
}
u.c: In function âfooâ:
u.c:10:5: error: address of register variable âaâ requested
     :
     ^
u.c:13:5: error: address of register variable âbâ requested
     );
     ^
u.c:14:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^