* lang_clang/analyze/graph_code_clang.ml: extract location info, structured way
* lang_clang/analyze/graph_code_clang.ml: file hierarchy
* lang_clang/analyze/graph_code_clang.ml: add defs func, typedefs
* lang_clang/analyze/graph_code_clang.ml: support for more defs
* lang_clang/analyze/graph_code_clang.ml: reorga