Add experimental support for Java 11 class files

[Godin]

No description provided.

[marchof]

@Godin Is there a reason that we use native ASM support for Java 11 but still use the BytecodeVersion trick for Java 10?

[marchof]

@Godin I found two more places where the new Java version should be added:

• InstrSupportTest.needFrames_should_return_true_for_versions_greater_than_or_equal_to_1_6()
• ClassFileVersionsTest

[Godin]

@marchof updated InstrSupportTest and ClassFileVersionsTest. IMO we should find a way to reduce number of places that require non functional mechanical update.

Cleanup from V10 is unrelated to Java 11, so will do it separately.

[marchof]

@Godin You're right about reducing numbers of places, where we encode class file versions. Maybe something like

int[] SUPPORTED_VERSIONS;

in BytecodeVersion could be a solution.