Add instructions for building CLANG/LLVM

Author: allentiak

README.md

@@ -15,7 +15,7 @@ Binary packages for Linux, Mac OS and Windows are built from time to time and
 made available on
 [SourceForge](http://sourceforge.net/projects/mozart-oz/files/).
 
-Mac support is provided for 10.8.x and recent versions (2.x) of Aquamacs. 
+Mac support is provided for 10.8.x and recent versions (2.x) of Aquamacs.
 
 The binary distribution requires that you have installed Tcl/Tk 8.5 on your
 system.
@@ -40,6 +40,11 @@ In order to build Mozart 2, you need the following tools on your computer:
 *   Tcl/Tk 8.5 or 8.6 (with development files)
 *   emacs
 
+For building CLANG/LLVM:
+*   LibXML2-dev (tested with version 2.9.3)
+*   OCaml-findlib
+*   libCTypes-OCaml-dev (>= 0.4 - available in Debian Unstable as of Jan. 2016)
+
 On Linux, use your favorite package manager to grab these tools. Refer to the
 specialized Readmes for recommendations on Mac OS and Windows.