Add JSON.pm to third_party

third_party/JSON/JSON-2.59/t/xe04support_by_pp.t

Index: third_party/JSON/JSON-2.59/t/xe04support_by_pp.t
diff --git a/third_party/JSON/JSON-2.59/t/xe04support_by_pp.t b/third_party/JSON/JSON-2.59/t/xe04support_by_pp.t
new file mode 100644
index 0000000000000000000000000000000000000000..f8c88734e2ad83092ecd37b3b33e63912c49bed2
--- /dev/null
+++ b/third_party/JSON/JSON-2.59/t/xe04support_by_pp.t
@@ -0,0 +1,22 @@
+use strict;
+use Test::More;
+BEGIN { plan tests => 3 };
+
+BEGIN { $ENV{PERL_JSON_BACKEND} = 1; }
+
+use JSON -support_by_pp;
+
+SKIP: {
+    skip "can't use JSON::XS.", 3, unless( JSON->backend->is_xs );
+
+my $json = new JSON;
+
+
+is($json->escape_slash(0)->allow_nonref->encode("/"), '"/"');
+is($json->escape_slash(1)->allow_nonref->encode("/"), '"\/"');
+is($json->escape_slash(0)->allow_nonref->encode("/"), '"/"');
+
+
+}
+__END__
+