wasmtime-component-macro: struct and consts created for flags! must be pub (#5030)

* wasmtime-component-macro: struct and consts created for flags! must be pub

* addd empty and all constructors to flags

crates/component-macro/src/lib.rs

@@ -1081,7 +1081,7 @@ fn expand_flags(flags: &Flags) -> Result<TokenStream> {
 
         let name = format_ident!("{}", name);
 
-        constants.extend(quote!(const #name: Self = Self { #fields };));
+        constants.extend(quote!(pub const #name: Self = Self { #fields };));
     }
 
     let generics = syn::Generics {
@@ -1128,14 +1128,23 @@ fn expand_flags(flags: &Flags) -> Result<TokenStream> {
 
     let expanded = quote! {
         #[derive(Copy, Clone, Default)]
-        struct #name { #fields }
+        pub struct #name { #fields }
 
         impl #name {
             #constants
 
-            fn as_array(&self) -> [u32; #count] {
+            pub fn as_array(&self) -> [u32; #count] {
                 #as_array
             }
+
+            pub fn empty() -> Self {
+                Self::default()
+            }
+
+            pub fn all() -> Self {
+                use std::ops::Not;
+                Self::default().not()
+            }
         }
 
         impl std::cmp::PartialEq for #name {