allow custom derives on enums

Custom derives are just as useful on enums as they are on structs; not
supporting this was an oversight.

Adds a test that will fail to compile if the custom derive doesn't work
on enums. This test fails without the codegen fix.

1 files changed, 7 insertions, 0 deletions

diff --git a/bindgen-integration/cpp/Test.h b/bindgen-integration/cpp/Test.h
index ad71b0f6..eee1974c 100644
--- a/bindgen-integration/cpp/Test.h
+++ b/bindgen-integration/cpp/Test.h
@@ -234,3 +234,10 @@ typedef union {
 } Coord;
 
 Coord coord(double x, double y, double z, double t);
+
+// Used to test custom derives on enum. See `test_custom_derive`.
+enum MyOrderedEnum {
+  MICRON,
+  METER,
+  LIGHTYEAR,
+};