Test with storage struct containing external function.

test/libsolidity/semanticTests/functionTypes/struct_with_external_function.sol

@@ -0,0 +1,34 @@
+struct S {
+    uint16 a;
+    function() external returns (uint) x;
+    uint16 b;
+}
+contract Flow {
+    S[2] t;
+
+    function X() public pure returns (uint) {
+        return 1;
+    }
+
+    function Y() public pure returns (uint) {
+        return 2;
+    }
+
+    constructor() {
+        t[0].a = 0xff07;
+        t[0].b = 0xff07;
+        t[1].x = this.Y;
+        t[1].a = 0xff07;
+        t[1].b = 0xff07;
+        t[0].x = this.X;
+    }
+
+    function f() public returns (uint, uint) {
+        return (t[0].x(), t[1].x());
+    }
+}
+
+// ====
+// compileViaYul: also
+// ----
+// f() -> 1, 2