Function instr_replace_reg_resize 

pub unsafe extern "C" fn instr_replace_reg_resize(
    instr: *mut instr_t,
    old_reg: reg_id_t,
    new_reg: reg_id_t,
) -> bool_

Replaces all instances of \p old_reg (or any size variant) in \p instr’s operands with \p new_reg. Resizes \p new_reg to match sub-full-size uses of \p old_reg. Returns whether it replaced anything.