Codechange: Replace all usages of alloca/AllocaM with more modern/less discouraged alternatives

src/waypoint_cmd.cpp

@@ -264,7 +264,7 @@ CommandCost CmdBuildRailWaypoint(DoCommandFlag flags, TileIndex start_tile, Axis
 		wp->UpdateVirtCoord();
 
 		const StationSpec *spec = StationClass::Get(spec_class)->GetSpec(spec_index);
-		byte *layout_ptr = AllocaM(byte, count);
+		byte *layout_ptr = new byte[count];
 		if (spec == nullptr) {
 			/* The layout must be 0 for the 'normal' waypoints by design. */
 			memset(layout_ptr, 0, count);
@@ -291,6 +291,7 @@ CommandCost CmdBuildRailWaypoint(DoCommandFlag flags, TileIndex start_tile, Axis
 			YapfNotifyTrackLayoutChange(tile, AxisToTrack(axis));
 		}
 		DirtyCompanyInfrastructureWindows(wp->owner);
+		delete[] layout_ptr;
 	}
 
 	return cost;