* Implement.
* Clean and doc
* Collect base addresses instead of leaking them
* Fix code for 1.25.
* Simplify $assert
* Use AbiParam::special.
* Use &mut self in base_addr
With new versions of cretonne-codegen:
- Non-colocated calls are emitted as a movabs with an indirect call.
This uses an Abs8 relocation.
- Colocated calls are emitted as direct calls, but the "+ 4"
adjustment is now folded into the addend, so we don't need to
handle it explicitly in the X86PCRel4 code anymore.
This begins reorganizing how translation and compilation occur, and
setting up infrastructure for imports/exports and relocations. It
splits parts out of StandaloneRuntime, forming Module, Compilation,
and Instance structs, which can be used more independently.
It also simplifies the command-line interface, in a step towards
making simple tools that just expose the functionality of the
libraries.
