Problem running constant pool checker over Java8 code

[aclement]

If the ConstantPoolChecker is in use, it can't cope with Java8 elements. For example: https://github.com/ratpack/example-ratpack-gradle-java-app

[SerCeMan]

:+1:

[danhyun]

:+1: would love to have this working :)

[danveloper]

:+1:

[johnrengelman]

:+1:

[KQGamble]

:+1:

[myott]

:+1: