Make sure all handler indices are ints.

Prior to this, some indices would be nums; one because the construct "$a+$b"
returns a num, even if both variables are ints (fixed by using logical or
instead, since those are the semantics we actually wanted anyways), and one
because "+@array" also returns a num (fixed by using nqp::elems instead).
Direct compilation of JAST nodes to bytecode.
Remove dependence of JASTCompiler on static caches.

First attempt at this attached static caches of the various JAST::Node type
objects in the compiler class, which caused failures under the evalserver, as
the type objects form the first compile would be reused for all subsequent
compiles. Now, we only cache the type objects per compilation.

The Rakudo sanity tests now pass.
Merge branch 'master' into jastcompiler
Actually save line annotations in JASTCompiler.

Fixes Rakudo spectest failures.
Update bootstrap compiler to have direct JAST compilation.
Remove old JAST compilation functionality.
Merge branch 'jastcompiler'