Add JSON.pm to third_party

third_party/JSON/JSON-2.59/t/10_pc_keysort.t

Index: third_party/JSON/JSON-2.59/t/10_pc_keysort.t
diff --git a/third_party/JSON/JSON-2.59/t/10_pc_keysort.t b/third_party/JSON/JSON-2.59/t/10_pc_keysort.t
new file mode 100644
index 0000000000000000000000000000000000000000..823e5a6842a69fbd3fe85d33efaf4fe1264f56df
--- /dev/null
+++ b/third_party/JSON/JSON-2.59/t/10_pc_keysort.t
@@ -0,0 +1,20 @@
+# copied over from JSON::PC and modified to use JSON
+# copied over from JSON::XS and modified to use JSON
+
+use Test::More;
+use strict;
+BEGIN { plan tests => 1 };
+
+BEGIN { $ENV{PERL_JSON_BACKEND} = "JSON::backportPP"; }
+
+use JSON;
+#########################
+
+my ($js,$obj);
+my $pc = JSON->new->canonical(1);
+
+$obj = {a=>1, b=>2, c=>3, d=>4, e=>5, f=>6, g=>7, h=>8, i=>9};
+
+$js = $pc->encode($obj);
+is($js, q|{"a":1,"b":2,"c":3,"d":4,"e":5,"f":6,"g":7,"h":8,"i":9}|);
+