Augment planner/stepper getters/setters

Marlin/enum.h

 #ifndef __ENUM_H__
 #define __ENUM_H__
 
+#include "MarlinConfig.h"
+
 /**
  * Axis indices as enumerated constants
  *

Marlin/planner.cpp

 } // buffer_line()
 
 /**
- * Directly set the planner XYZ position (hence the stepper positions).
+ * Directly set the planner XYZ position (and stepper positions)
+ * converting mm (or angles for SCARA) into steps.
  *
  * On CORE machines stepper ABC will be translated from the given XYZ.
  */
 }
 
 /**
- * Directly set the planner E position (hence the stepper E position).
+ * Setters for planner position (also setting stepper position).
  */
-void Planner::set_e_position_mm(const float& e) {
-  position[E_AXIS] = lround(e * axis_steps_per_mm[E_AXIS]);
-  stepper.set_e_position(position[E_AXIS]);
-  previous_speed[E_AXIS] = 0.0;
+void Planner::set_position_mm(const AxisEnum axis, const float& v) {
+  position[axis] = lround(v * axis_steps_per_mm[axis]);
+  stepper.set_position(axis, v);
+  previous_speed[axis] = 0.0;
 }
 
 // Recalculate the steps/s^2 acceleration rates, based on the mm/s^2

Marlin/planner.h

 #define PLANNER_H
 
 #include "types.h"
+#include "enum.h"
 #include "MarlinConfig.h"
 
 #if HAS_ABL
      * Clears previous speed values.
      */
     static void set_position_mm(ARG_X, ARG_Y, ARG_Z, const float& e);
+    static void set_position_mm(const AxisEnum axis, const float& v);
+
+    static FORCE_INLINE void set_z_position_mm(const float& z) { set_position_mm(Z_AXIS, z); }
+    static FORCE_INLINE void set_e_position_mm(const float& e) { set_position_mm(E_AXIS, e); }
 
     /**
      * Sync from the stepper positions. (e.g., after an interrupted move)
     static void sync_from_steppers();
 
     /**
-     * Set the E position (mm) of the planner (and the E stepper)
-     */
-    static void set_e_position_mm(const float& e);
-
-    /**
      * Does the buffer have any blocks queued?
      */
     static bool blocks_queued() { return (block_buffer_head != block_buffer_tail); }

Marlin/stepper.cpp

   CRITICAL_SECTION_END;
 }
 
+void Stepper::set_position(const AxisEnum &axis, const long& v) {
+  CRITICAL_SECTION_START;
+  count_position[axis] = v;
+  CRITICAL_SECTION_END;
+}
+
 void Stepper::set_e_position(const long& e) {
   CRITICAL_SECTION_START;
   count_position[E_AXIS] = e;

Marlin/stepper.h

     // Set the current position in steps
     //
     static void set_position(const long& x, const long& y, const long& z, const long& e);
+    static void set_position(const AxisEnum& a, const long& v);
     static void set_e_position(const long& e);
 
     //