Current HS code has Method::_intrinsic_id as u1, which limits the number of possible intrinsics to 255. It served us well so far, but over time we have collected a significant number of intrinsics. JDK 9 projects, including Compact Strings and VarHandles introduced even more. In VarHandles, we have already brought the number of intrinsics over 255, and so we need to adjust the _intrinsic_id type to at least u2 to handle them all.

This has implications for footprint, VM code that assumes "(u1) id" cast is safe, Serviceability Agent, etc, and so it should be done straight in the upstream, not redone for each subproject that goes over the brink.