fixup: add fwd decls to test case

 - struct with normal fwd decl and blocklisted definition ignored
 - struct with blocklisted fwd decl and normal definition emitted

Author: daviddrysdale

tests/expectations/tests/blocklist-file.rs

@@ -61,3 +61,34 @@ fn bindgen_test_layout_SizedIntegers() {
         )
     );
 }
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct StructWithBlocklistedFwdDecl {
+    pub b: u8,
+}
+#[test]
+fn bindgen_test_layout_StructWithBlocklistedFwdDecl() {
+    assert_eq!(
+        ::std::mem::size_of::<StructWithBlocklistedFwdDecl>(),
+        1usize,
+        concat!("Size of: ", stringify!(StructWithBlocklistedFwdDecl))
+    );
+    assert_eq!(
+        ::std::mem::align_of::<StructWithBlocklistedFwdDecl>(),
+        1usize,
+        concat!("Alignment of ", stringify!(StructWithBlocklistedFwdDecl))
+    );
+    assert_eq!(
+        unsafe {
+            &(*(::std::ptr::null::<StructWithBlocklistedFwdDecl>())).b
+                as *const _ as usize
+        },
+        0usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(StructWithBlocklistedFwdDecl),
+            "::",
+            stringify!(b)
+        )
+    );
+}

tests/headers/blocklist-file.hpp

@@ -1,5 +1,8 @@
 // bindgen-flags: --blocklist-file ".*/blocklisted/file.*" -- -Itests/headers
 
+// Forward declaration of struct that's defined in a blocklisted file.
+struct StructWithBlocklistedDefinition;
+
 #include "blocklisted/file.hpp"
 #include "blocklisted/fake-stdint.h"
 
@@ -8,3 +11,8 @@ struct SizedIntegers {
     uint16_t y;
     uint32_t z;
 };
+
+// Actual definition of struct that has a forward declaration in a blocklisted file.
+struct StructWithBlocklistedFwdDecl {
+    uint8_t b;
+};

tests/headers/blocklisted/file.hpp

@@ -17,3 +17,10 @@ namespace foo {
 namespace bar {
   void NamespacedFunction();
 }
+
+
+struct StructWithBlocklistedFwdDecl;
+
+struct StructWithBlocklistedDefinition {
+    StructWithBlocklistedFwdDecl* other;
+};