Moves the alloc_dbginfo type to Debuginfo, to avoid a circular
dependency on architectures that use Branch_relaxation.
This commit generates frame tables with allocation sizes on all
architectures, but does not yet update the allocation code for
non-amd64 backends.
* Various file moves in the middle end: this is the first stage of improving separation between the middle end and backend.
* Creation of file_formats/ directory (with associated file moves) to hold the definitions of compilation artifact formats.
* Creation of lambda/ directory (with associated file moves) to hold Lambda language definition files, transformation passes and construction passes from Typedtree.
* Disable (hopefully temporarily) dynlink, debugger and ocamldoc for the dune build.
Stephen Dolan
Mark Shinwell