[PATCH] [OCaml] [cmake] Add CMake buildsystem for OCaml.

[Peter Zotov]

This CMake buildsystem port should be functionally equivalent to the autoconf one, including:
  * Proper handling of dependencies between OCaml libraries and between OCaml and C++ libraries, including with parallel builds;
  * Embedding of equivalent linker flags in cma/cmxa libraries (not identical, as CMake shared library split LLVM harder);
  * Installation;
  * Generating documentation.

I have tested it extensively using the following matrix, which is a superset of the lit tests:

linux × shared/static builds × autoconf/cmake (for comparison) × ocaml toplevel/ocamlc/ocamlc -custom/ocamlopt.

All combinations appear to work.

http://reviews.llvm.org/D6102