Old K+R compatibility goo in c-decl.c::duplicate_decls - preserve?

[Zack Weinberg]

While working on a bunch of outstanding c-decl.c issues I came across
these special cases in duplicate_decls:

  /* Permit char *foo () to match void *foo (...) if not pedantic,
     if one of them came from a system header file.  */

  /* Permit void foo (...) to match int foo (...) if the latter is the
     definition and implicit int was used.  See
     c-torture/compile/920625-2.c.  */

  /* Permit char *foo (int, ...); followed by char *foo ();
     if not pedantic.  */


All of these relax C90's requirements for the sake of pre-standard
code.  We've removed most of the support for pre-standard code; I
would like to know whether people think these special cases can be
removed too.  This would be a small but nontrivial simplification to
duplicate_decls.

zw