Move blocks outside Lexer#advance

[eregon]

• This gives big compilation size and time benefit, because the local variables of Lexer#advance are no longer captured by those blocks (even if unused due to Ruby semantics and Proc#binding).
• See Parser::Lexer#advance method is too big for JIT compilers #871 (comment)

[eregon]

It would be good to add a test to ensure Lexer#advance remains without block/proc/lambda/lambda-literal inside it, as it matters quite a bit for performance and compilation size/time.
I'm not able to do that now though (it's already past midnight here and I'm traveling tomorrow).

[eregon]

The failing test shows these lambda also access some ivars, so they can't be constants, I'll move them in initialize then.

[eregon]

Done, CI should be green now.

[iliabylich]

Thanks!

[eregon]

I missed that 5b2135e#diff-894f90ef5e566bf82a7b031fd82df1aece88eaac96cae6483feba8c020a63761R884 also did this partially in a slightly different way, which also works but has the slight perf disadvantage of allocating a Proc per such method call vs one per Lexer instance.
So, my apologies about the potential conflicts (should be just a few lines though).