Use push_back instead of emplace_back

Since we can't have the performance improvements provided by
emplace_back and its construct-in-place mechanism without adding a lot
of code (constructors for the struct), just use push_back to emphasize
the fact that we are constructing the objects then putting them into the
list.
This is fine though, we don't actually need performance in this case.

src/PrimeTower/PrimeTower.cpp

@@ -53,7 +53,7 @@ PrimeTower::PrimeTower()
             const double brim_radius_factor = std::pow((1.0 - static_cast<double>(z) / static_cast<double>(base_height)), base_curve_magnitude);
             const coord_t extra_radius = std::llrint(static_cast<double>(base_extra_radius) * brim_radius_factor);
             const coord_t total_radius = tower_radius + extra_radius;
-            base_occupied_outline_.emplace_back(OccupiedOutline{ PolygonUtils::makeDisc(middle_, total_radius, circle_definition_), total_radius });
+            base_occupied_outline_.push_back(OccupiedOutline{ PolygonUtils::makeDisc(middle_, total_radius, circle_definition_), total_radius });
         }
     }
 }

src/PrimeTower/PrimeTowerInterleaved.cpp

@@ -88,7 +88,7 @@ std::map<LayerIndex, std::vector<PrimeTower::ExtruderToolPaths>> PrimeTowerInter
             {
                 if (toolpaths_at_layer.empty())
                 {
-                    toolpaths_at_layer.emplace_back(ExtruderToolPaths{ last_extruder_support, ClosedLinesSet(), prime_next_outer_radius, inner_support_radius });
+                    toolpaths_at_layer.push_back(ExtruderToolPaths{ last_extruder_support, ClosedLinesSet(), prime_next_outer_radius, inner_support_radius });
                 }
 
                 ExtruderToolPaths& last_extruder_toolpaths = toolpaths_at_layer.back();
@@ -117,7 +117,7 @@ void PrimeTowerInterleaved::polishExtrudersUses(LayerVector<std::vector<Extruder
         // Make sure we always have something to print
         if (extruders_use_at_layer.empty())
         {
-            extruders_use_at_layer.emplace_back(ExtruderUse{ last_used_extruder, ExtruderPrime::Support });
+            extruders_use_at_layer.push_back(ExtruderUse{ last_used_extruder, ExtruderPrime::Support });
         }
         else if (std::all_of(
                      extruders_use_at_layer.begin(),