8022524: Memory leaks in nashorn sources and tests found by jhat analysis
Reviewed-by: attila, hannesw
<test/script/basic/JDK-8012164.js>.error(test/script/basic/JDK-8012164.js:38)
<test/script/basic/JDK-8012164.js>.func(test/script/basic/JDK-8012164.js:33)
<test/script/basic/JDK-8012164.js>.<program>(test/script/basic/JDK-8012164.js:47)