sort global symbols deterministically within GSI bucket

src/linker/lnk_debug_info.c

@@ -1839,6 +1839,7 @@ THREAD_POOL_TASK_FUNC(lnk_move_global_symbols_to_gsi)
         CV_SymbolNode *n = &nodes[i];
         n->prev = n->next = 0;
         n->data = cv_symbol_from_ptr(symbol_arr[i]);
+        n->data.offset = i;
         gsi_push_(gsi, symbol_hashes[i], n);
       }
     }

src/linker/pdb_ext/pdb_builder.c

@@ -1827,7 +1827,11 @@ gsi_symbol_is_before(void *raw_a, void *raw_b)
   if (a_name.size != b_name.size) {
     is_before = a_name.size < b_name.size;
   } else {
-    is_before = str8_compar_ignore_case(&a_name, &b_name) < 0;
+    int cmp = str8_compar_ignore_case(&a_name, &b_name);
+    if (cmp == 0) {
+      cmp = u64_compar(&a->offset, &b->offset);
+    }
+    is_before = cmp < 0;
   }
 
   return is_before;