Add JSON.pm to third_party

third_party/JSON/JSON-2.58/t/xe19_xs_and_suportbypp.t

+#! perl
+
+# https://rt.cpan.org/Public/Bug/Display.html?id=52847
+
+use strict;
+use Test::More;
+
+BEGIN { plan tests => 2 };
+BEGIN { $ENV{PERL_JSON_BACKEND} = 1; }
+
+use JSON -support_by_pp;
+
+SKIP: {
+    skip "can't use JSON::XS.", 2, unless( JSON->backend->is_xs );
+
+    my $json = JSON->new->allow_barekey;
+
+    for (1..2) {
+        is_deeply( test($json, q!{foo:"foo"}!   ), {foo=>'foo'} );
+        JSON->new->allow_singlequote(0);
+    }
+}
+
+
+sub test {
+    my ($coder, $str) = @_;
+    my $rv;
+    return $rv if eval { $rv = $coder->decode($str); 1 };
+    chomp( my $e = $@ );
+    return "died with \"$e\"";
+};
+
+
+