Add filter for Records

[Godin]

I propose to filter methods toString, hashCode and equals that compiler generates for Records (JEP 359), leaving accessor methods untouched, which is consistent with what we do for Kotlin data classes.

---

For

record Point(int x, int y) {
    public static void main(String[] args) {
        new Point(0, 0);
    }
}

Using java -version

openjdk version "14-ea" 2020-03-17
OpenJDK Runtime Environment (build 14-ea+30-1385)
OpenJDK 64-Bit Server VM (build 14-ea+30-1385, mixed mode, sharing)

javac \
    --enable-preview \
    --release 14 \
    -d classes \
    Point.java

java \
    --enable-preview \
    -javaagent:jacocoagent.jar \
    -cp classes \
    Point

Generation of report

java -jar jacococli.jar \
    report jacoco.exec \
    --classfiles classes \
    --sourcefiles src \
    --html report

before this change produces

and after

[marchof]

Out of curiosity: Why does surefire require this flag?

[Godin]

@marchof enablement of Preview Features by --enable-preview flag is required both at compile and at run time - see Preview Language and VM Features (JEP 12), otherwise we'll get

java.lang.UnsupportedClassVersionError: Preview features are not enabled for org/jacoco/core/test/validation/java14/RecordsTest (class file version 58.65535). Try running with '--enable-preview'

[marchof]

Right, thanks!

[ice1000]

Should we also ignore the accessors?

[ice1000]

See #1215