partial PL_statbuf removal

partial PL_statbuf removal

Perl_nextargv has to have access to the Stat_t that is written to inside
S_openn_cleanup or else run/switches.t, io/argv.t, io/inplace.t, and
io/iprefix.t will fail. Removing the uses of PL_statbuf that are using
PL_statbuf due to historical reason, and not using PL_statbuf to pass data
between different funcs/different callstacks. This patch makes it easier to
remove PL_statbuf in the future since the number uses of it has been
reduced.

-in Perl_apply move SETERRNO before tot--; so the branch can be combined
 with other "tot--;" branches by CC optmizer
-combine 2 Perl_croak(aTHX_ "Illegal suidscript"); statements in
 S_validate_suid to make code look simpler, drop my_perl arg for space
 efficiency on threads of rarely executed code