Update TryWithResourcesJavacFilter for javac 11

[Godin]

javac 11 EA starting from b7 and up to latest (as of today) b24 contains http://hg.openjdk.java.net/jdk/jdk/rev/c2a3a2aa2475 ( JDK-8194978 ), which changes bytecode generation for try-with-resource. Our TryWithResourcesJavacFilter does not detect this new bytecode.

Based on analysis of change, description of desugaring in javadoc of method makeTwrTy in class com/sun/tools/javac/comp/Lower from b24, and practical observations:

• there is no null check of primaryExc anymore
• as with javac 9 when resource is initialized with new, then null check of resource is omitted
• synthetic method $closeResource (that was introduced in javac 9) not generated anymore

To execute our validation tests with javac 11 EA in absence of full support of JDK 11:

$ javac -version
javac 11-ea

$ mvn clean verify \
    -pl org.jacoco.core,org.jacoco.core.test.validation.java7 \
    -Djacoco.skip -Dbytecode.version=10

[Godin]

@marchof We need to continue work towards JDK 11 support - AFAIK initial release candidate is planned on 2018/08/16. So could you please have a look on this new filter? While it is similar to existing, I think that better to have them separate - existing one is already quite complex.

[marchof]

Looks good to me. Especially as it is properly backed by tests. For final merge the change log should be updated.

I would love to have a more fluent matcher API. Maybe some more isXXX would help to make it more readable. But this is a different story.

[marchof]

@Godin Would it be already possible to add an JDK 11 build to Travis?

[Godin]

@marchof

change log should be updated

Done, please check.

I would love to have a more fluent matcher API.

Same from my side, but as usual - baby steps, baby steps 😉

Would it be already possible to add an JDK 11 build to Travis?

Definitely! Was planning and will do so right after merge of this PR, so that javac 11 passes our tests 😆 and doesn't lead to build failure.