Add JSON.pm to third_party

third_party/JSON/JSON-2.59/t/e15_tie_ixhash.t

Index: third_party/JSON/JSON-2.59/t/e15_tie_ixhash.t
diff --git a/third_party/JSON/JSON-2.59/t/e15_tie_ixhash.t b/third_party/JSON/JSON-2.59/t/e15_tie_ixhash.t
new file mode 100644
index 0000000000000000000000000000000000000000..9e8991d2f36969329f96f435857acf9723a55788
--- /dev/null
+++ b/third_party/JSON/JSON-2.59/t/e15_tie_ixhash.t
@@ -0,0 +1,44 @@
+
+use strict;
+use Test::More;
+BEGIN { plan tests => 2 };
+
+BEGIN { $ENV{PERL_JSON_BACKEND} = "JSON::backportPP"; }
+
+use JSON;
+
+# from https://rt.cpan.org/Ticket/Display.html?id=25162
+
+SKIP: {
+    eval {require Tie::IxHash};
+    skip "Can't load Tie::IxHash.", 2 if ($@);
+
+    my %columns;
+    tie %columns, 'Tie::IxHash';
+
+    %columns = (
+    id => 'int',
+    1 => 'a',
+    2 => 'b',
+    3 => 'c',
+    4 => 'd',
+    5 => 'e',
+    );
+
+    my $js = to_json(\%columns);
+    is( $js, q/{"id":"int","1":"a","2":"b","3":"c","4":"d","5":"e"}/ );
+
+    $js = to_json(\%columns, {pretty => 1});
+    is( $js, <<'STR' );
+{
+   "id" : "int",
+   "1" : "a",
+   "2" : "b",
+   "3" : "c",
+   "4" : "d",
+   "5" : "e"
+}
+STR
+
+}
+