self-referential c record imports

examples/interop/recursive/app/main.bro

@@ -0,0 +1,16 @@
+native :: import "../include/native.h"
+
+# Exercises a self-referential imported C record (`struct Node { struct Node *next; int value; }`):
+# the importer must not recurse forever populating it, and the checker must accept the
+# self-referential `?*mut Node` field as C-layout-compatible.
+
+main :: func() i32 {
+	node native.Node = native.Node { next = none, value = 7 }
+	if node.next |_| {
+		return 1
+	}
+	if node.value == 7 {
+		return 0
+	}
+	return 2
+}

examples/interop/recursive/include/native.h

@@ -0,0 +1,4 @@
+typedef struct Node {
+	struct Node *next;
+	int value;
+} Node;