Add --no-convert-direct-calls option to Simplify
Add --no-convert-direct-calls option to Simplify

This option prevents converting direct function calls into the
calls-by-pointers if the address of the function has been taken
somewhere.  Calls from inside of structures are converted anyway.

(A small debug print fix has been also applied)

samuelhavron/obliv-c,samuelhavron/obliv-c,samuelhavron/obliv-c,samuelhavron/obliv-c