Open requested system packages for javac

[snjeza]

The related issues/commits:

• bug - javac can not navigate to method [pre-release version] #3900
• Compile bug with javac #3897
• bug - javac can not reference class in other gradle module #3885
• eclipse-jdtls/eclipse-jdt-core-incubator@bf3c8ce

[mickaelistria]

another one is freshly necessary: --add-opens java.compiler/javax.tools=ALL-UNNAMED. Note that the exact list is available in the org.eclipse.jdt.core.javac/META-INF/p2.inf` file and should be part of the .ini file generated with the JDT-LS product.
Ideally, instead of hardcoding/duplicating those here, they should be read from one of the upstream files.

[snjeza]

another one is freshly necessary: --add-opens java.compiler/javax.tools=ALL-UNNAMED. Note that the exact list is available in the org.eclipse.jdt.core.javac/META-INF/p2.inf` file and should be part of the .ini file generated with the JDT-LS product.

I have added it - 4f51d5c#diff-2d9ec606b265a83596a734df153c4ef01523700dc2576dcf1a80c9092c14d6d3R143

[mickaelistria]

Good to be merged ASAP IMO

[rgrunber]

@snjeza , if you have time, I would also update https://github.com/eclipse-jdtls/eclipse.jdt.ls/blob/1d41ddee3b461fcd8b30eadb3d7dd6abf56814ed/pom.xml#L343 .

[snjeza]

if you have time, I would also update https://github.com/eclipse-jdtls/eclipse.jdt.ls/blob/1d41ddee3b461fcd8b30eadb3d7dd6abf56814ed/pom.xml#L343 .

@rgrunber Please check eclipse-jdtls/eclipse.jdt.ls#3351