FieldValuesParser implementation for the eclipse compiler

[snicoll]

When running the build with the eclipse compiler, the default values cannot be harvested and written in the meta-data because there is no suitable implementation of FieldValuesParser.

[philwebb]

This is because the eclipse compiler is different from the JDK one. Some of the initial FieldValuesParser work was based on things that lombok does, they have an eclipse equivalent so perhaps we can use a similar technique.

[snicoll]

Duplicates #7226 - We'll have to find another technique for Java 9 anyway and that one should be compiler independent.

[philwebb]

Reopening to check that e15b3e4 actually fixed this.

[snicoll]

It did not, good catch. I am still discussing with the openjdk team to find a better way to deal with this.

[hansenc]

For anyone else running into it, this also affects errorprone's javac (from their JDK 8 instructions).