make PERL_USE_SAFE_PUTENV the default and the only option

Now environ isn't owned by Perl and calling setenv/putenv in XS code
will no longer result in memory corruption.

Fixes #19399

1 files changed, 0 insertions, 4 deletions

diff --git a/makedef.pl b/makedef.pl
index 0d594043d0..99090cb417 100644
--- a/makedef.pl
+++ b/makedef.pl
@@ -353,10 +353,6 @@ else {
 			 );
 }
 
-if ($define{'PERL_USE_SAFE_PUTENV'}) {
-    ++$skip{PL_use_safe_putenv};
-}
-
 unless ($define{'USE_ITHREADS'}) {
     ++$skip{PL_thr_key};
     ++$skip{PL_user_prop_mutex};