[10.x] Remove obsolete function_exists('enum_exists') calls

src/Illuminate/Database/Eloquent/Concerns/HasAttributes.php

@@ -1592,9 +1592,7 @@ protected function isEnumCastable($key)
             return false;
         }
 
-        if (function_exists('enum_exists') && enum_exists($castType)) {
-            return true;
-        }
+        return enum_exists($castType);
     }
 
     /**

src/Illuminate/Database/Eloquent/Relations/Concerns/InteractsWithDictionary.php

@@ -23,8 +23,7 @@ protected function getDictionaryKey($attribute)
                 return $attribute->__toString();
             }
 
-            if (function_exists('enum_exists') &&
-                $attribute instanceof UnitEnum) {
+            if ($attribute instanceof UnitEnum) {
                 return $attribute instanceof BackedEnum ? $attribute->value : $attribute->name;
             }
 

src/Illuminate/Database/Query/Builder.php

@@ -3703,11 +3703,7 @@ public function addBinding($value, $type = 'where')
      */
     public function castBinding($value)
     {
-        if (function_exists('enum_exists') && $value instanceof BackedEnum) {
-            return $value->value;
-        }
-
-        return $value;
+        return $value instanceof BackedEnum ? $value->value : $value;
     }
 
     /**

src/Illuminate/Http/Concerns/InteractsWithInput.php

@@ -402,7 +402,6 @@ public function date($key, $format = null, $tz = null)
     public function enum($key, $enumClass)
     {
         if ($this->isNotFilled($key) ||
-            ! function_exists('enum_exists') ||
             ! enum_exists($enumClass) ||
             ! method_exists($enumClass, 'tryFrom')) {
             return null;

src/Illuminate/Routing/UrlGenerator.php

@@ -484,9 +484,7 @@ public function toRoute($route, $parameters, $absolute)
                     ? $value->{$route->bindingFieldFor($key)}
                     : $value;
 
-            return function_exists('enum_exists') && $value instanceof BackedEnum
-                ? $value->value
-                : $value;
+            return $value instanceof BackedEnum ? $value->value : $value;
         })->all();
 
         return $this->routeUrl()->to(

src/Illuminate/Support/Reflector.php

@@ -150,7 +150,7 @@ public static function isParameterBackedEnumWithStringBackingType($parameter)
     {
         $backedEnumClass = (string) $parameter->getType();
 
-        if (function_exists('enum_exists') && enum_exists($backedEnumClass)) {
+        if (enum_exists($backedEnumClass)) {
             $reflectionBackedEnum = new ReflectionEnum($backedEnumClass);
 
             return $reflectionBackedEnum->isBacked()

src/Illuminate/Validation/Rules/Enum.php

@@ -38,7 +38,7 @@ public function passes($attribute, $value)
             return true;
         }
 
-        if (is_null($value) || ! function_exists('enum_exists') || ! enum_exists($this->type) || ! method_exists($this->type, 'tryFrom')) {
+        if (is_null($value) || ! enum_exists($this->type) || ! method_exists($this->type, 'tryFrom')) {
             return false;
         }