make recipe selection and buffers of smelter and reprocessing plant behave like other buildings, except that a recipe may be chosen automatically

src/lib/sim/BuildingBuffers.h

@@ -18,10 +18,6 @@
 // REQ-MAT-OUTPUT-BUFFER).
 void initBuffers(Building& b, const RecipeDef& recipe);
 
-// Buffers for an auto-recipe building (Smelter, Reprocessing Plant), unioned over
-// every recipe of its type (REQ-BLD-SMELTER, REQ-BLD-REPROCESSING).
-void initAutoBuffers(const GameConfig& config, Building& b);
-
 // Buffers for a shipyard: its schematic's materials plus those of every placed
 // module (REQ-BLD-SHIPYARD).
 void initShipyardBuffers(const GameConfig& config, Building& b);