glsl-in: support for storage image types

src/front/glsl/ast.rs

@@ -55,6 +55,9 @@ pub struct Overload {
     pub kind: FunctionKind,
     /// Wheter this function was already defined or is just a prototype
     pub defined: bool,
+    /// Wheter this overload is the one provided by the language or has
+    /// been redeclared by the user (builtins only)
+    pub internal: bool,
     /// Wheter or not this function returns void (nothing)
     pub void: bool,
 }
@@ -139,13 +142,16 @@ pub enum QualifierKey<'a> {
     String(Cow<'a, str>),
     /// Used for `std140` and `std430` layout qualifiers
     Layout,
+    /// Used for image formats
+    Format,
 }
 
 #[derive(Debug)]
 pub enum QualifierValue {
     None,
     Uint(u32),
     Layout(StructLayout),
+    Format(crate::StorageFormat),
 }
 
 #[derive(Debug, Default)]