Add JSON.pm to third_party

third_party/JSON/JSON-2.58/t/x17_strange_overload.t

Index: third_party/JSON/JSON-2.58/t/x17_strange_overload.t
diff --git a/third_party/JSON/JSON-2.58/t/x17_strange_overload.t b/third_party/JSON/JSON-2.58/t/x17_strange_overload.t
new file mode 100644
index 0000000000000000000000000000000000000000..440bfe24a00507ff0929389b1ccdce64655f4562
--- /dev/null
+++ b/third_party/JSON/JSON-2.58/t/x17_strange_overload.t
@@ -0,0 +1,20 @@
+use strict;
+use Test::More;
+BEGIN { plan tests => 2 };
+
+BEGIN { $ENV{PERL_JSON_BACKEND} = 1; }
+
+SKIP: {
+    eval q{
+        use JSON::XS;
+        use JSON ();
+    };
+
+    skip "can't use JSON::XS.", 2, if $@;
+    skip "JSON::XS version < " . JSON->require_xs_version, 2
+            if JSON::XS->VERSION < JSON->require_xs_version;
+
+    is("" . JSON::XS::true(), 'true');
+    is("" . JSON::true(),     'true');
+}
+