refactor: roadblock runtime_data moved from building common class

Author: dalerank

src/building/building.h

@@ -214,10 +214,6 @@ class building {
     short formation_id;
     union impl_data_t {
         char data[512] = { 0 };
-
-        struct {
-            short exceptions;
-        } roadblock;
     } data;
     int tax_income_or_storage;
     unsigned char house_days_without_food;

src/building/building_roadblock.cpp

@@ -20,15 +20,16 @@ bool building_roadblock::force_draw_flat_tile(painter &ctx, tile2i tile, vec2i p
 }
 
 void building_roadblock::bind_dynamic(io_buffer *iob, size_t version) {
-    iob->bind(BIND_SIGNATURE_UINT8, &data.roadblock.exceptions);
+    auto &d = runtime_data();
+    iob->bind(BIND_SIGNATURE_UINT8, &d.exceptions);
 }
 
 void building_roadblock::set_permission(e_permission p) {
     const int permission_bit = 1 << p;
-    data.roadblock.exceptions ^= permission_bit;
+    runtime_data().exceptions ^= permission_bit;
 }
 
 bool building_roadblock::get_permission(e_permission p) {
     const int permission_bit = 1 << p;
-    return (data.roadblock.exceptions & permission_bit);
+    return (runtime_data().exceptions & permission_bit);
 }

src/building/building_roadblock.h

@@ -7,11 +7,17 @@ class building_routeblock : public building_impl {
 public:
     building_routeblock(building &b) : building_impl(b) {}
 
+    struct runtime_data_t {
+        short exceptions;
+    };
+
     virtual building_routeblock *dcast_routeblock() override { return this; }
 
     virtual void set_permission(e_permission) {}
     virtual bool get_permission(e_permission) { return false; }
 
+    runtime_data_t &runtime_data() { return *(runtime_data_t *)data.data; }
+    const runtime_data_t &runtime_data() const { return *(runtime_data_t *)data.data; }
 };
 
 class building_roadblock : public building_routeblock {