Use bit-size typedefs for some stepper vars

Marlin/stepper.cpp

       Stepper::counter_Z = 0,
       Stepper::counter_E = 0;
 
-volatile unsigned long Stepper::step_events_completed = 0; // The number of step events executed in the current block
+volatile uint32_t Stepper::step_events_completed = 0; // The number of step events executed in the current block
 
 #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
 
     #endif
 
     // Calculate new timer value
-    unsigned short timer, step_rate;
-    if (step_events_completed <= (unsigned long)current_block->accelerate_until) {
+    uint16_t timer, step_rate;
+    if (step_events_completed <= (uint32_t)current_block->accelerate_until) {
 
       MultiU24X32toH16(acc_step_rate, acceleration_time, current_block->acceleration_rate);
       acc_step_rate += current_block->initial_rate;
       #if ENABLED(LIN_ADVANCE)
 
         if (current_block->use_advance_lead)
-          current_estep_rate[TOOL_E_INDEX] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
+          current_estep_rate[TOOL_E_INDEX] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
 
         if (current_block->use_advance_lead) {
           #if ENABLED(MIXING_EXTRUDER)
             MIXING_STEPPERS_LOOP(j)
-              current_estep_rate[j] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
+              current_estep_rate[j] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
           #else
-            current_estep_rate[TOOL_E_INDEX] = ((unsigned long)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
+            current_estep_rate[TOOL_E_INDEX] = ((uint32_t)acc_step_rate * current_block->e_speed_multiplier8) >> 8;
           #endif
         }
 
         eISR_Rate = (timer >> 2) * step_loops / abs(e_steps[TOOL_E_INDEX]);
       #endif
     }
-    else if (step_events_completed > (unsigned long)current_block->decelerate_after) {
+    else if (step_events_completed > (uint32_t)current_block->decelerate_after) {
       MultiU24X32toH16(step_rate, deceleration_time, current_block->acceleration_rate);
 
       if (step_rate <= acc_step_rate) { // Still decelerating?
         if (current_block->use_advance_lead) {
           #if ENABLED(MIXING_EXTRUDER)
             MIXING_STEPPERS_LOOP(j)
-              current_estep_rate[j] = ((unsigned long)step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
+              current_estep_rate[j] = ((uint32_t)step_rate * current_block->e_speed_multiplier8 * current_block->step_event_count / current_block->mix_event_count[j]) >> 8;
           #else
-            current_estep_rate[TOOL_E_INDEX] = ((unsigned long)step_rate * current_block->e_speed_multiplier8) >> 8;
+            current_estep_rate[TOOL_E_INDEX] = ((uint32_t)step_rate * current_block->e_speed_multiplier8) >> 8;
           #endif
         }
 

Marlin/stepper.h

 
     // Counter variables for the Bresenham line tracer
     static long counter_X, counter_Y, counter_Z, counter_E;
-    static volatile unsigned long step_events_completed; // The number of step events executed in the current block
+    static volatile uint32_t step_events_completed; // The number of step events executed in the current block
 
     #if ENABLED(ADVANCE) || ENABLED(LIN_ADVANCE)
       static unsigned char old_OCR0A;