a53fa0dfbf
Remove "JVM_TARGET: 1.6" directive from box tests and remove tests with JVM target 1.8. By default, box tests are run with JVM target 1.6, and there's an additional configuration `codegenTarget8Jvm8Test` that runs all box tests with JVM target 1.8. Also, remove box tests with JVM target 1.6. They aren't needed because even if we manage to generate incorrect bytecode with target 1.6, the corresponding box tests will catch that