Actually *using* the location in the failure handler would be
incorrect, as it adds noise to backtraces involving partial exception
handlers. This is now properly documented.
We still take the caller location (which is currently ignored) for
consistency with other toplevel Matching functions, and because that
may become useful if we want to add more error-reporting or warnings
in compile_matching.
* 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.