Having everybody and their uncle reading and writing fields out of a.code and stubs.code was making assembler work hard. This replaces most reads with accessors, and all writes with structured friends of X64SAssembler.
Also rename array_inline.h to array_data-inl.h
We were punting on this, but it's a pretty easy translation, and it makes calling functions from inside namespaces much faster. Closes #814
Makes things more consistent, at least within this directory.
Keith Adams