fmt: add `pub` modifier for public enums

vlib/v/fmt/fmt.v

@@ -150,6 +150,9 @@ fn (f mut Fmt) stmt(node ast.Stmt) {
 			f.writeln('}')
 		}
 		ast.EnumDecl {
+			if it.is_pub {
+				f.write('pub ')
+			}
 			f.writeln('enum $it.name {')
 			for val in it.vals {
 				f.writeln('\t' + val)

vlib/v/fmt/tests/simple_expected.vv

@@ -22,6 +22,16 @@ pub const (
 	i_am_pub_const = true
 )
 
+pub enum PubEnum {
+	foo
+	bar
+}
+
+enum PrivateEnum {
+	foo
+	bar
+}
+
 struct User {
 	name            string
 	age             int

vlib/v/fmt/tests/simple_input.vv

@@ -23,6 +23,14 @@ pub const (
 i_am_pub_const=true
 )
 
+pub enum PubEnum{
+	foo bar
+}
+
+enum PrivateEnum{
+	foo bar
+}
+
 struct User {
 	name string
 	age int