* Introducing codefrag: a new runtime module to work with code fragments
This module collects all the operations on code fragments performed in
various places of the runtime systems. Applies both to bytecode and
to native code.
The implementation is based on skiplists, so that "lookup fragment by
PC" and "lookup fragment by number" are efficient (logarithmic in the
number of code fragments). "Lookup fragment by digest" remains
linear-time.
The new module also improves the handling of digests: now it is
possible to mark a code fragment as "no digest" i.e. not marshal-able.
* Use the new "codefrag" runtime module for marshaling and for the
debugger interface
Replace the previous handling of code fragments with calls to the
functions provided by the "codefrag" runtime module.
This commit adds dynlink support for ocamldebug. As a side effect, it also:
- factorizes the various functions searching for a code fragment into one,
called [caml_find_code_fragment];
- removes the [caml_register_code_fragment], which does not seem to
be used anywhere, and which clearly should not be used by external code.