Let B::Deparse know about the [perl #20444] fix.

With the previous commit:

$ ./perl -Ilib -MO=Deparse -e'"foo" =~ (1?/foo/:/bar/)'
'foo' =~ /foo/;
-e syntax OK

So the Deparse output no longer matches what perl does. With
this commit:

$ ./perl -Ilib -MO=Deparse -e'"foo" =~ (1?/foo/:/bar/)'
'foo' =~ ($_ =~ /foo/);
-e syntax OK

2 files changed, 19 insertions, 2 deletions

diff --git a/dist/B-Deparse/Deparse.pm b/dist/B-Deparse/Deparse.pm
index f446f2ad3d..92f27476f2 100644
--- a/dist/B-Deparse/Deparse.pm
+++ b/dist/B-Deparse/Deparse.pm
@@ -4221,6 +4221,7 @@ sub matchop {
     }
     my $quote = 1;
     my $extended = ($op->pmflags & PMf_EXTENDED);
+    my $rhs_bound_to_defsv;
     if (null $kid) {
 	my $unbacked = re_unback($op->precomp);
 	if ($extended) {
@@ -4232,6 +4233,7 @@ sub matchop {
 	carp("found ".$kid->name." where regcomp expected");
     } else {
 	($re, $quote) = $self->regcomp($kid, 21, $extended);
+	$rhs_bound_to_defsv = 1 if $kid->first->first->flags & OPf_SPECIAL;
     }
     my $flags = "";
     $flags .= "c" if $op->pmflags & PMf_CONTINUE;
@@ -4250,7 +4252,13 @@ sub matchop {
     }
     $re = $re . $flags if $quote;
     if ($binop) {
-	return $self->maybe_parens("$var =~ $re", $cx, 20);
+	return
+	 $self->maybe_parens(
+	  $rhs_bound_to_defsv
+	   ? "$var =~ (\$_ =~ $re)"
+	   : "$var =~ $re",
+	  $cx, 20
+	 );
     } else {
 	return $re;
     }
diff --git a/dist/B-Deparse/t/deparse.t b/dist/B-Deparse/t/deparse.t
index 3a7d2aa8eb..0fc3b6c87e 100644
--- a/dist/B-Deparse/t/deparse.t
+++ b/dist/B-Deparse/t/deparse.t
@@ -17,7 +17,7 @@ BEGIN {
     require feature;
     feature->import(':5.10');
 }
-use Test::More tests => 89;
+use Test::More tests => 90;
 use Config ();
 
 use B::Deparse;
@@ -645,3 +645,12 @@ pop;
 pop();
 ####
 pop @_;
+####
+# 82 [perl #20444]
+"foo" =~ (1 ? /foo/ : /bar/);
+"foo" =~ (1 ? y/foo// : /bar/);
+"foo" =~ (1 ? s/foo// : /bar/);
+>>>>
+'foo' =~ ($_ =~ /foo/);
+'foo' =~ ($_ =~ tr/fo//);
+'foo' =~ ($_ =~ s/foo//);