Option to force X or Y to home first when homing the other axis

.travis.yml

   - opt_enable REPRAP_DISCOUNT_SMART_CONTROLLER SDSUPPORT EEPROM_SETTINGS
   - opt_enable BLINKM PCA9632 RGB_LED NEOPIXEL_LED AUTO_POWER_CONTROL
   - opt_enable AUTO_BED_LEVELING_LINEAR Z_MIN_PROBE_REPEATABILITY_TEST DEBUG_LEVELING_FEATURE SKEW_CORRECTION SKEW_CORRECTION_FOR_Z SKEW_CORRECTION_GCODE
-  - opt_enable_adv FWRETRACT MAX7219_DEBUG LED_CONTROL_MENU CASE_LIGHT_ENABLE CASE_LIGHT_USE_NEOPIXEL
+  - opt_enable_adv FWRETRACT MAX7219_DEBUG LED_CONTROL_MENU CASE_LIGHT_ENABLE CASE_LIGHT_USE_NEOPIXEL CODEPENDENT_XY_HOMING
   - opt_set ABL_GRID_POINTS_X 16
   - opt_set ABL_GRID_POINTS_Y 16
   - opt_set_adv FANMUX0_PIN 53
   - opt_set TEMP_SENSOR_4 999
   - opt_set TEMP_SENSOR_BED 1
   - opt_enable AUTO_BED_LEVELING_UBL DEBUG_LEVELING_FEATURE G26_MESH_EDITING ENABLE_LEVELING_FADE_HEIGHT EEPROM_SETTINGS EEPROM_CHITCHAT G3D_PANEL SKEW_CORRECTION
-  - opt_enable_adv CUSTOM_USER_MENUS I2C_POSITION_ENCODERS BABYSTEPPING BABYSTEP_XY LIN_ADVANCE NANODLP_Z_SYNC
+  - opt_enable_adv CUSTOM_USER_MENUS I2C_POSITION_ENCODERS BABYSTEPPING BABYSTEP_XY LIN_ADVANCE NANODLP_Z_SYNC QUICK_HOME
   - build_marlin_pio ${TRAVIS_BUILD_DIR} ${TEST_PLATFORM}
   #
-  # Add a Sled Z Probe, do non-segmented moves, use Japanese language
+  # Add a Sled Z Probe, use UBL Cartesian moves, use Japanese language
   #
   - opt_set LANGUAGE kana_utf8
-  - opt_enable Z_PROBE_SLED
+  - opt_enable Z_PROBE_SLED SKEW_CORRECTION SKEW_CORRECTION_FOR_Z SKEW_CORRECTION_GCODE
   - opt_disable SEGMENT_LEVELED_MOVES
   - opt_enable_adv BABYSTEP_ZPROBE_OFFSET DOUBLECLICK_FOR_Z_BABYSTEPPING
   - build_marlin_pio ${TRAVIS_BUILD_DIR} ${TEST_PLATFORM}

Marlin/Configuration_adv.h

 // When G28 is called, this option will make Y home before X
 //#define HOME_Y_BEFORE_X
 
+// Enable this if X or Y can't home without homing the other axis first.
+//#define CODEPENDENT_XY_HOMING
+
 // @section machine
 
 #define AXIS_RELATIVE_MODES {false, false, false, false}

Marlin/src/gcode/calibrate/G28.cpp

 
     #endif
 
+    // Home Y (before X)
     #if ENABLED(HOME_Y_BEFORE_X)
 
-      // Home Y
-      if (home_all || homeY) {
+      if (home_all || homeY
+        #if ENABLED(CODEPENDENT_XY_HOMING)
+          || homeX
+        #endif
+      ) {
         HOMEAXIS(Y);
         #if ENABLED(DEBUG_LEVELING_FEATURE)
           if (DEBUGGING(LEVELING)) DEBUG_POS("> homeY", current_position);
     #endif
 
     // Home X
-    if (home_all || homeX) {
+    if (home_all || homeX
+      #if ENABLED(CODEPENDENT_XY_HOMING) && DISABLED(HOME_Y_BEFORE_X)
+        || homeY
+      #endif
+    ) {
 
       #if ENABLED(DUAL_X_CARRIAGE)
 
       #endif
     }
 
+    // Home Y (after X)
     #if DISABLED(HOME_Y_BEFORE_X)
-      // Home Y
       if (home_all || homeY) {
         HOMEAXIS(Y);
         #if ENABLED(DEBUG_LEVELING_FEATURE)

Marlin/src/inc/SanityCheck.h

 #endif
 
 /**
- * Homing Bump
+ * Homing
  */
 #if X_HOME_BUMP_MM < 0 || Y_HOME_BUMP_MM < 0 || Z_HOME_BUMP_MM < 0
   #error "[XYZ]_HOME_BUMP_MM must be greater than or equal to 0."
 #endif
 
+#if ENABLED(CODEPENDENT_XY_HOMING)
+  #if ENABLED(QUICK_HOME)
+    #error "QUICK_HOME is incompatible with CODEPENDENT_XY_HOMING."
+  #elif IS_KINEMATIC
+    #error "CODEPENDENT_XY_HOMING requires a Cartesian setup."
+  #endif
+#endif
+
 /**
  * Make sure Z_SAFE_HOMING point is reachable
  */