This change more accurately implements ECMAScript prototype chains.
This includes using the prototype chain to lookup properties when
necessary, and copying them down upon writes.
This still isn't 100% faithful -- for example, classes and
constructor functions should be represented as real objects with
the prototype link -- so that examples like those found here will
work: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/constructor.
I've updated marapongo/mu#70 with additional details about this.
I'm sure we'll be forced to fix this as we encounter more "dynamic"
JavaScript. (In fact, it would be interesting to start running the
pre-ES6 output of TypeScript through the compiler as test cases.)
See http://www.ecma-international.org/ecma-262/6.0/#sec-objects
for additional details on the prototype chaining semantics.
This adds scaffolding but no real functionality yet, as part of
marapongo/mu#41. I am landing this now because I need to take a
not-so-brief detour to gut and overhaul the core of the existing
compiler (parsing, semantic analysis, binding, code-gen, etc),
including merging the new pkg/pack contents back into the primary
top-level namespaces (like pkg/ast and pkg/encoding).
After that, I can begin driving the compiler to achieve the
desired effects of mu compile, first and foremost, and then plan
and apply later on.
