Make enums into implicit char

Marlin/src/module/endstops.h

@@ -30,7 +30,7 @@
 #include "../inc/MarlinConfig.h"
 #include <stdint.h>
 
-enum EndstopEnum {
+enum EndstopEnum : char {
   X_MIN,
   Y_MIN,
   Z_MIN,

Marlin/src/module/motion.h

@@ -288,7 +288,7 @@ void homeaxis(const AxisEnum axis);
  */
 #if ENABLED(DUAL_X_CARRIAGE)
 
-  enum DualXMode {
+  enum DualXMode : char {
     DXC_FULL_CONTROL_MODE,  // DUAL_X_CARRIAGE only
     DXC_AUTO_PARK_MODE,     // DUAL_X_CARRIAGE only
     DXC_DUPLICATION_MODE
@@ -308,7 +308,7 @@ void homeaxis(const AxisEnum axis);
 
 #elif ENABLED(DUAL_NOZZLE_DUPLICATION_MODE)
 
-  enum DualXMode {
+  enum DualXMode : char {
     DXC_DUPLICATION_MODE = 2
   };
 

Marlin/src/module/planner.h

@@ -44,7 +44,7 @@
   #include "../libs/vector_3.h"
 #endif
 
-enum BlockFlagBit {
+enum BlockFlagBit : char {
   // Recalculate trapezoids on entry junction. For optimization.
   BLOCK_BIT_RECALCULATE,
 
@@ -60,7 +60,7 @@ enum BlockFlagBit {
   BLOCK_BIT_CONTINUED
 };
 
-enum BlockFlag {
+enum BlockFlag : char {
   BLOCK_FLAG_RECALCULATE          = _BV(BLOCK_BIT_RECALCULATE),
   BLOCK_FLAG_NOMINAL_LENGTH       = _BV(BLOCK_BIT_NOMINAL_LENGTH),
   BLOCK_FLAG_BUSY                 = _BV(BLOCK_BIT_BUSY),

Marlin/src/module/temperature.h

@@ -49,7 +49,7 @@
 /**
  * States for ADC reading in the ISR
  */
-enum ADCSensorState {
+enum ADCSensorState : char {
   #if HAS_TEMP_0
     PrepareTemp_0,
     MeasureTemp_0,
@@ -610,7 +610,7 @@ class Temperature {
 
     #if ENABLED(THERMAL_PROTECTION_HOTENDS) || HAS_THERMALLY_PROTECTED_BED
 
-      typedef enum TRState { TRInactive, TRFirstHeating, TRStable, TRRunaway } TRstate;
+      typedef enum TRState : char { TRInactive, TRFirstHeating, TRStable, TRRunaway } TRstate;
 
       static void thermal_runaway_protection(TRState * const state, millis_t * const timer, const float &current, const float &target, const int8_t heater_id, const uint16_t period_seconds, const uint16_t hysteresis_degc);