RFR:8186180:Symbol.__proto__ results in error with format string placeholder

[Priya Lakshmi Muthuswamy]

Hi,

Please review JDK-8186180 : Symbol.__proto__ results in error with 
format string placeholder

JBS: https://bugs.openjdk.java.net/browse/JDK-8186180
webrev: http://cr.openjdk.java.net/~pmuthuswamy/8186180/webrev.00/

Thanks,
Priya