1. Loading from image was not throwing an error if image file was non-existent. Fixed by making load_from_image() return an integer and checking this return value.
2. Commented out check for non-empty black set in cleanup_memory() as this will fail if loading from image and exiting immediately.
3. Incorrect if clause in compile_to_c() fixed
4. compile_function() fixed to avoid duplicates in called_closures and redefinition of the function's symbol (in the case of recursive functions). Also return the existing function if it already exists in the 'native_functions' hashtable.
1. Introduced new global to keep track of when we're in the middle of a macro expansion.
2. COMPILE operator (now a macro that calls SIMPLIFY) will ignore debug information. This replaces the original COMPILE which has been renamed to COMPILE1.
3. Single TCCState
4. New macros in library (third, fourth)
5. Removed commented out code in vm.c