little fix to function arg validation

Author: gavinking

hibernate-core/src/main/java/org/hibernate/query/sqm/produce/function/ArgumentTypesValidator.java

@@ -23,6 +23,7 @@
 import org.hibernate.sql.ast.tree.SqlAstNode;
 import org.hibernate.sql.ast.tree.expression.Expression;
 import org.hibernate.type.JavaObjectType;
+import org.hibernate.type.SqlTypes;
 import org.hibernate.type.descriptor.java.JavaType;
 import org.hibernate.type.descriptor.java.spi.JdbcTypeRecommendationException;
 import org.hibernate.type.descriptor.jdbc.JdbcTypeIndicators;
@@ -199,7 +200,7 @@ private void checkType(int count, String functionName, FunctionParameterType typ
 				}
 				break;
 			case STRING:
-				if ( !isCharacterType(code) && code != ENUM_UNKNOWN_JDBC_TYPE ) {
+				if ( !isCharacterType(code) && code != SqlTypes.ENUM && code != ENUM_UNKNOWN_JDBC_TYPE) {
 					throwError(type, javaType, functionName, count);
 				}
 				break;