Resolve review comment

Author: encounter

objdiff-core/src/obj/mdebug.rs

@@ -101,13 +101,21 @@ pub(super) fn parse_line_info_mdebug(
             }
 
             let local_index = pdr.isym as u32;
-            let mut size = None;
+            let mut end_value = None;
             for sym in &symbols[global_sym_index..sym_end] {
                 if sym.st == ST_END && sym.index == local_index {
-                    size = Some(sym.value);
+                    end_value = Some(sym.value);
                     break;
                 }
             }
+            let Some(end_value) = end_value else {
+                continue;
+            };
+            let start_value = start_symbol.value;
+            let mut size = end_value.checked_sub(start_value);
+            if size.is_none() || size == Some(0) {
+                size = end_value.checked_sub(pdr.addr);
+            }
             let Some(size) = size else {
                 continue;
             };