This PR:

• adds a file specific to ARM64 (to be revisited), with the list of all predefined macros;
• fixes a fatal error when an argument of a function, other than the last one, is an array;
• adds back explicitly simple structures;
• adds strict conversion and changes type_letters to be relaxed conversion (which doesn't care about qualifiers);
• change the default behaviour on the generator to always add an E character when the function is a GO[W]M;
• adds more supported casts in expression evaluation;
• removes "Warning: '...' is already in the declaration map with the same type"