Add support for enums with the wrapped static functions feature (#2415)

Author: Urgau

bindgen-tests/tests/expectations/tests/generated/wrap_static_fns.c

@@ -12,3 +12,5 @@ int takes_alias__extern(func f) asm("takes_alias__extern");
 int takes_alias__extern(func f) { return takes_alias(f); }
 int takes_qualified__extern(const int *const *arg) asm("takes_qualified__extern");
 int takes_qualified__extern(const int *const *arg) { return takes_qualified(arg); }
+enum foo takes_enum__extern(const enum foo f) asm("takes_enum__extern");
+enum foo takes_enum__extern(const enum foo f) { return takes_enum(f); }

bindgen-tests/tests/expectations/tests/wrap-static-fns.rs

@@ -31,3 +31,11 @@ static inline int takes_alias(func f) {
 static inline int takes_qualified(const int *const *arg) {
     return **arg;
 }
+
+enum foo {
+    BAR = 0x0,
+};
+
+static inline enum foo takes_enum(const enum foo f) {
+    return f;
+}

bindgen-tests/tests/headers/wrap-static-fns.h

@@ -311,6 +311,14 @@ impl<'a> CSerialize<'a> for Type {
                     CompKind::Union => write!(writer, "union {}", name)?,
                 };
             }
+            TypeKind::Enum(_enum_ty) => {
+                if self.is_const() {
+                    write!(writer, "const ")?;
+                }
+
+                let name = item.canonical_name(ctx);
+                write!(writer, "enum {}", name)?;
+            }
             ty => {
                 return Err(CodegenError::Serialize {
                     msg: format!("Cannot serialize type kind {:?}", ty),