* Exclude Jazzer classes from coverage reports
* Generate file-level coverage data for Java
Adds per-file coverage information to llvm-cov style *.json files for
Java targets.
This provides full CI Fuzz support for "jvm" projects.
Coverage is collected by running the fuzz targets with the JaCoCo agent
in Jazzer's no instrumentation mode.
Since JaCoCo does not support llvm-cov style coverage reports, a simple
Python helper creates it using the information contained in the JaCoCo
XML report.
As the Java build process does not maintain a mapping between source
files and build artifacts and JaCoCo needs to be passed the root folder
of the package tree, we use the Maven directory layout convention to
heuristically detect these roots.