Minor bug fixes.

- G38.x was not printing correctly in the $G g-code state reports. Now
fixed.

- Potential bug regarding volatile variables inside a struct. It has
never been a problem in v0.9, but ran into this during v1.0
development. Just to be safe, the fixes are applied here.

- Updated pre-built firmwares with these two bug fixes.

grbl/system.h

@@ -72,20 +72,20 @@ typedef struct {
   uint8_t abort;                 // System abort flag. Forces exit back to main loop for reset.
   uint8_t state;                 // Tracks the current state of Grbl.
   uint8_t suspend;               // System suspend bitflag variable that manages holds, cancels, and safety door.
-
-  volatile uint8_t rt_exec_state;  // Global realtime executor bitflag variable for state management. See EXEC bitmasks.
-  volatile uint8_t rt_exec_alarm;  // Global realtime executor bitflag variable for setting various alarms.
-
+  
   int32_t position[N_AXIS];      // Real-time machine (aka home) position vector in steps. 
                                  // NOTE: This may need to be a volatile variable, if problems arise.                             
 
-  uint8_t homing_axis_lock;       // Locks axes when limits engage. Used as an axis motion mask in the stepper ISR.
-  volatile uint8_t probe_state;   // Probing state value.  Used to coordinate the probing cycle with stepper ISR.
   int32_t probe_position[N_AXIS]; // Last probe position in machine coordinates and steps.
   uint8_t probe_succeeded;        // Tracks if last probing cycle was successful.
+  uint8_t homing_axis_lock;       // Locks axes when limits engage. Used as an axis motion mask in the stepper ISR.
 } system_t;
 extern system_t sys;
 
+volatile uint8_t sys_probe_state;   // Probing state value.  Used to coordinate the probing cycle with stepper ISR.
+volatile uint8_t sys_rt_exec_state;  // Global realtime executor bitflag variable for state management. See EXEC bitmasks.
+volatile uint8_t sys_rt_exec_alarm;  // Global realtime executor bitflag variable for setting various alarms.
+
 
 // Initialize the serial protocol
 void system_init();