Standardize MAD to use create_entity.h (#1612)

More of the same unifying of the stages to all use the shared files.

Required a single ifdef to match. Nothing crazy.

src/st/create_entities_horizontal.h

@@ -20,11 +20,15 @@ void CreateEntitiesToTheLeft(s16 posX) {
         FindFirstEntityToTheLeft(posX - g_ScrollDeltaX);
         g_LayoutObjPosHorizontal = LAYOUT_OBJ_POSITION_BACKWARD;
     }
-
+// MAD only runs once to create one entity to the left.
+#if !defined(VERSION_BETA)
     while (true) {
+#else
+    if (true) {
+#endif
         if (g_LayoutObjHorizontal[LAYOUT_OBJ_POS_X] == LAYOUT_OBJ_START ||
             posX > g_LayoutObjHorizontal[LAYOUT_OBJ_POS_X]) {
-            break;
+            return;
         }
 
         expected = 0;

src/st/mad/create_entity.c

@@ -1,56 +1,4 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 #include "mad.h"
 
-// BSS START size = 0x16
-static u16* g_LayoutObjHorizontal;
-static u16* g_LayoutObjVertical;
-static u8 g_LayoutObjPosHorizontal;
-STATIC_PAD_BSS(3);
-static u8 g_LayoutObjPosVertical;
-STATIC_PAD_BSS(3);
-// END BSS
-
-#include "../st_private.h"
-
-#include "../create_entity_from_layout.h"
-#include "../create_entity_in_range.h"
-#include "../find_entity_horizontal.h"
-#include "../create_entities_right.h"
-
-/*
- * n.b.! This is different from every other stage's `CreateEntitiesToTheLeft`.
- * It will at most create 1 entity to the left and then exit with the horizontal
- * array pointer updated to the next element in the sequence.
- */
-void CreateEntitiesToTheLeft(s16 posX) {
-    u8 flag;
-    s32 expected = 0;
-
-    if (posX < 0) {
-        posX = 0;
-    }
-
-    if (g_LayoutObjPosHorizontal == LAYOUT_OBJ_POSITION_FORWARD) {
-        FindFirstEntityToTheLeft(posX - g_ScrollDeltaX);
-        g_LayoutObjPosHorizontal = LAYOUT_OBJ_POSITION_BACKWARD;
-    }
-
-    if (g_LayoutObjHorizontal[LAYOUT_OBJ_POS_X] == LAYOUT_OBJ_START ||
-        g_LayoutObjHorizontal[LAYOUT_OBJ_POS_X] < posX) {
-        return;
-    }
-
-    flag = (g_LayoutObjHorizontal[LAYOUT_OBJ_SLOT] >> 8) + 0xff;
-    expected = 0;
-    if (flag == 0xFF ||
-        ((g_entityDestroyed[flag >> 5] & (1 << (flag & 0x1f))) == expected)) {
-        CreateEntityWhenInVerticalRange(g_LayoutObjHorizontal);
-    }
-    g_LayoutObjHorizontal -= 5;
-}
-
-#include "../find_entity_vertical.h"
-#include "../create_entities_vertical.h"
-#include "../init_room_entities.h"
-#include "../update_room_position.h"
-#include "../create_entity_from_entity.h"
+#include "../create_entity.h"