RFR: JDK-8222035: Unused variable declaration causes inference error

[Vicente Romero]

Hi all,

Please review fix for [1] at [2]. The issue is random and very hard to 
reproduce with a regression test. Apart from the use of non-ordering 
preserving data structures, the root cause was early resolution of the 
inference context which was leading, in this case, to inexact 
instantiation of some inference variables.

Thanks,
Vicente

[1] https://bugs.openjdk.java.net/browse/JDK-8222035
[2] http://cr.openjdk.java.net/~vromero/8222035/webrev.00/