Cleanup: use new BLI_assert_unreachable macro

source/blender/python/bmesh/bmesh_py_types.c

@@ -3984,7 +3984,7 @@ PyObject *BPy_BMElem_CreatePyObject(BMesh *bm, BMHeader *ele)
     case BM_LOOP:
       return BPy_BMLoop_CreatePyObject(bm, (BMLoop *)ele);
     default:
-      BLI_assert(0);
+      BLI_assert_unreachable();
       PyErr_SetString(PyExc_SystemError, "internal error");
       return NULL;
   }

source/blender/python/bmesh/bmesh_py_types_customdata.c

@@ -56,7 +56,7 @@ static CustomData *bpy_bm_customdata_get(BMesh *bm, char htype)
       return &bm->ldata;
   }
 
-  BLI_assert(0);
+  BLI_assert_unreachable();
   return NULL;
 }
 
@@ -958,7 +958,7 @@ PyObject *BPy_BMLayerAccess_CreatePyObject(BMesh *bm, const char htype)
       type = &BPy_BMLayerAccessLoop_Type;
       break;
     default: {
-      BLI_assert(0);
+      BLI_assert_unreachable();
       type = NULL;
       break;
     }