RFR: JDK 8194892: add compiler support for local-variable syntax for lambda parameters

[Vicente Romero]

Please review the implementation for JEP 323: Local-Variable Syntax for 
Lambda Parameters [1].
The specification has been made public at [2]. The current 
implementation for the spec can be found at [3].

Thanks,
Vicente


[1] https://bugs.openjdk.java.net/browse/JDK-8193259
[2] 
http://mail.openjdk.java.net/pipermail/amber-spec-experts/2018-February/000268.html
[3] http://cr.openjdk.java.net/~vromero/8194892/webrev.00/