Ahaggar: update the fncalls-match function with basic logic

* Add appropriate IDs for their corresponding hash_functions
* Add output_buffer_write() and substring_write() to quickly
  print buffer and sub strings
* Rename handle_output() to process_output()
* Check the match counter mcounter before processing function calls

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: add dump_decl_output() to dump function declaration

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: add extract_fnname() function

This function will allocate memory and copy the function name from
substring into that memory and return it.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>
Ahaggar: add the next_fncall_to_substring() function

This function will parse the output buffer searching for the next
function call to return and save it into the substring.

Signed-off-by: Djalal Harouni <tixxdz@opendz.org>