Potential fix for PL_HASH_RAND_BITS_ENABLED == 2

References: Perl#250

It seems that the unit test `t/run/xrunenv.t`
identifies an issue where we cannot reproduce a hash
randomization when using the DETERMINISTIC mode.

This is an attempt to fix it.
Need review from upstream.

Author: atoomic

hv.c

@@ -843,7 +843,7 @@ Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
      * reset the iterator randomizer if there is one.
      */
     in_collision = *oentry != NULL;
-    if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
+    if ( *oentry && PL_HASH_RAND_BITS_ENABLED == 1) {
         PL_hash_rand_bits++;
         PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
         if ( PL_hash_rand_bits & 1 ) {

t/run/xrunenv.t

@@ -61,7 +61,6 @@ sub runperl_and_capture {
   }
 }
 
-our $TODO;
 SKIP:
 {
     #skip "NO_PERL_HASH_ENV or NO_PERL_HASH_SEED_DEBUG set", 16
@@ -81,13 +80,9 @@ SKIP:
             my($out2, $err2) = runperl_and_capture( { %base_opts, PERL_HASH_SEED => $seed }, [ @print_keys ]);
             if ( $mode eq 'RANDOM' ) {
                 isnt ($out,$out2,"PERL_PERTURB_KEYS = $mode results in different key order with the same key");
-            } elsif ( $mode eq 'NO' ) {
-                is ($out,$out2,"PERL_PERTURB_KEYS = $mode allows one to recreate a random hash");
-            } elsif ( $mode eq 'DETERMINISTIC' ) {
-                local $TODO = q[need to check DETERMINISTIC mode];
+            } else {
                 is ($out,$out2,"PERL_PERTURB_KEYS = $mode allows one to recreate a random hash");
             }
-
             is ($err,$err2,"Got the same debug output when we set PERL_HASH_SEED and PERL_PERTURB_KEYS");
         }
     }