Enable Y and sanity-check CoreXZ (PR#2509)

Marlin/SanityCheck.h

@@ -312,4 +312,8 @@
     #error PROBE_SERVO_DEACTIVATION_DELAY has been replaced with DEACTIVATE_SERVOS_AFTER_MOVE and SERVO_DEACTIVATION_DELAY.
   #endif
 
+  #if defined(COREXZ) && defined(Z_LATE_ENABLE)
+    #error "Z_LATE_ENABLE can't be used with COREXZ."
+  #endif
+
 #endif //SANITYCHECK_H

Marlin/planner.cpp

@@ -607,6 +607,7 @@ float junction_deviation = 0.1;
       enable_x();
       enable_z();
     }
+    if (block->steps[Y_AXIS]) enable_y();
   #else
     if (block->steps[X_AXIS]) enable_x();
     if (block->steps[Y_AXIS]) enable_y();