Replace ptr = ptr.offset(1) increment patterns with in-place pointer arithmetic (#96)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Nuno Lopes <nuno.lopes@tecnico.ulisboa.pt>

Author: Copilot

libcc2rs/src/io.rs

@@ -112,7 +112,7 @@ pub fn fread_refcount(a0: AnyPtr, a1: u64, a2: u64, a3: Ptr<::std::fs::File>) ->
 
         for &byte in &buffer[..n] {
             dst.write(byte);
-            dst = dst.offset(1);
+            dst += 1;
         }
 
         read_bytes += n;

libcc2rs/src/rc.rs

@@ -641,7 +641,7 @@ impl<T> Iterator for StringIterator<T> {
         // skip the null terminator
         if self.ptr.get_offset() + 1 < self.ptr.len() {
             let value = self.ptr.clone();
-            self.ptr = self.ptr.offset(1);
+            self.ptr += 1;
             Some(value)
         } else {
             None