Factor out adding return type check.
Get return type checks in place.

Doesn't emit check code at all for unconstrained.
Some missing declaration_static.
Very simple cases of binder simplification.
assignunchecked should mean unchecked.
Only look for submethods on objects than can.
Add bind lowers on Moar for many common cases.
Lower typical proto-method signature.

Was missed in the first pass, and is very common.
Fix warning; diakopter++.
Lower signatures containing coercions.
More optimal Enum($val) implementation.
fix IO::Path.contents for moar
Lower slurpy array and some capture binds.
Get NQP with improvements/fixes.
Fix various closure-related issues.

In these places we wrongly fell back on auto-close, which is slow and
wrong.
Get NQP with JVM/Moar continuation improvements.
Fix GatherIter not to add a frame every take.

Fixes the typical case of StackOverflowException on the JVM, and leads
to far better gather/take performance on both MoarVM and JVM.
Micro-optimize GatherIter.
Some more ChangeLog entries.
prepend path in dir() when needed