testsuite/
        * g++.old-deja/g++.brendan/crash16.C: Function name is the correct 
        location for an error regarding a function.
        * g++.old-deja/g++.other/pmf3.C: Same.
        * g++.old-deja/g++.law/ctors5.C: Same.
        * g++.old-deja/g++.pt/explicit34.C: Same.
        * g++.dg/parse/error28.C: Same.
        * g++.dg/parse/error17.C: Same.
        * g++.dg/template/friend44.C: Same.
cp/
        * decl.c (duplicate_decls): Call error_at.
        (grokfndecl): New location argument.  Use location if available.
        (grokdeclarator): Pass declarator location to grokfndecl.
        * cp-tree.h (struct cp_declarator): Update comment for id_loc.
        * decl2.c (check_classfn): Use error_at.
        * parser.c (cp_parser_init_declarator): Set function_start_locus
        to brace location.
        (cp_parser_member_declaration): Set id_loc for function declarators.

From-SVN: r140379