t/op/magic.t clearing \%ENV is not safe in z/OS in ASCII mode")

This joins valgrind and vms with this characteristic

Author: khwilliamson

t/op/magic.t

@@ -53,6 +53,7 @@ $Is_MSWin32  = $^O eq 'MSWin32';
 $Is_VMS      = $^O eq 'VMS';
 $Is_os2      = $^O eq 'os2';
 $Is_Cygwin   = $^O eq 'cygwin';
+$Is_ZOS      = $^O eq 'os390';
 
 $PERL =
    ($Is_VMS     ? $^X      :
@@ -333,7 +334,9 @@ $^X = Cygwin::win_to_posix_path(Cygwin::posix_to_win_path($^X, 1));
 $0 = Cygwin::win_to_posix_path(Cygwin::posix_to_win_path($0, 1));
 EOX
     }
-    if ($^O eq 'os390' or $^O eq 'posix-bc') {  # no shebang
+    if (  ($Is_ZOS && ord "A" != 65)
+        or $^O eq 'posix-bc')
+    {  # no shebang
 	$headmaybe = <<EOH ;
     eval 'exec ./perl -S \$0 \${1+"\$\@"}'
         if 0;
@@ -827,8 +830,8 @@ SKIP: {
         if $Is_MSWin32 && is_miniperl;
 
  SKIP: {
-	skip("clearing \%ENV is not safe when running under valgrind or on VMS")
-	    if $ENV{PERL_VALGRIND} || $Is_VMS;
+	skip("clearing \%ENV is not safe when running under valgrind or on VMS or on z/OS in ASCII mode")
+	    if $ENV{PERL_VALGRIND} || $Is_VMS || ($Is_ZOS && ord "A" == 65);
 
 	    $PATH = $ENV{PATH};
 	    $SYSTEMROOT = $ENV{SYSTEMROOT} if exists $ENV{SYSTEMROOT}; # win32