make RC-stack-aware: unwrap pp_emptyavhv()

Remove the temporary wrapper from pp_emptyavhv()

Also fix some tests in array.t, which were expecting a temp empty array
ref to be prematurely freed. With PERL_RC_STACK, it's no longer
prematurely freed.

pp.c

@@ -5969,9 +5969,8 @@ PP(pp_anonlist)
 /* When an anonlist or anonhash will (1) be empty and (2) return an RV
  * pointing to the new AV/HV, the peephole optimizer can swap in this
  * simpler function and op_null the originally associated PUSHMARK. */
-PP_wrapped(pp_emptyavhv, 0,0)
+PP(pp_emptyavhv)
 {
-    dSP;
     OP * const op = PL_op;
     SV * rv;
     SV * const sv = MUTABLE_SV( newSV_type(
@@ -5996,19 +5995,18 @@ PP_wrapped(pp_emptyavhv, 0,0)
             save_clearsv(padentry);
         }
         if (GIMME_V == G_VOID) {
-            RETURN; /* skip extending and pushing */
+            return NORMAL; /* skip extending and pushing */
         }
+        rpp_xpush_1(rv);
     } else {
         /* Inlined newRV_noinc */
-        SV * refsv = newSV_type_mortal(SVt_IV);
+        SV * refsv = newSV_type(SVt_IV);
         SvRV_set(refsv, sv);
         SvROK_on(refsv);
-
-        rv = refsv;
+        rpp_extend(1);
+        rpp_push_1_norc(refsv);
     }
-
-    XPUSHs(rv);
-    RETURN;
+    return NORMAL; /* skip extending and pushing */
 }
 
 

t/op/array.t

@@ -265,21 +265,29 @@ is ($got, '');
 }
 
 sub test_arylen {
-    my $ref = shift;
+    my ($ref, , $fixed, $desc) = @_;
     local $^W = 1;
-    is ($$ref, undef, "\$# on freed array is undef");
+    # on RC builds, the temp [] array isn't prematurely freed:
+    # the \$# magic var keeps it alive.
+    my $is_rc = $fixed && (Internals::stack_refcounted() & 1);
+    is ($$ref, ($is_rc ? - 1 : undef), "$desc: \$# on freed array is undef");
     my @warn;
     local $SIG{__WARN__} = sub {push @warn, "@_"};
     $$ref = 1000;
-    is (scalar @warn, 1);
-    like ($warn[0], qr/^Attempt to set length of freed array/);
+    is (scalar @warn, ($is_rc ? 0 : 1), "$desc: number of warnings");
+    if ($is_rc) {
+        pass("$desc: pass");
+    }
+    else {
+        like ($warn[0], qr/^Attempt to set length of freed array/, "$desc: msg");
+    }
 }
 
 {
     my $a = \$#{[]};
     # Need a new statement to make it go out of scope
-    test_arylen ($a);
-    test_arylen (do {my @a; \$#a});
+    test_arylen ($a, 1, "\$a");
+    test_arylen (do {my @a; \$#a}, 0, "do {}");
 }
 
 {