Add test cases.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_directly_recursive_dynamic_array.sol

@@ -0,0 +1,7 @@
+contract Test {
+    struct MyStructName {
+        address addr;
+        MyStructName[] x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/structs/recursion/struct_definition_directly_recursive_fixed_array.sol

@@ -0,0 +1,8 @@
+contract Test {
+    struct MyStructName {
+        address addr;
+        MyStructName[1] x;
+    }
+}
+// ----
+// TypeError: (20-96): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_complex.sol

@@ -0,0 +1,18 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName4[1] x;
+    }
+    struct MyStructName2 {
+        MyStructName1 x;
+    }
+    struct MyStructName3 {
+        MyStructName2[1] x;
+    }
+    struct MyStructName4 {
+        MyStructName3 x;
+    }
+}
+// ----
+// TypeError: (20-121): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_dynamic_array1.sol

@@ -0,0 +1,11 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2[] x;
+    }
+    struct MyStructName2 {
+        MyStructName1 x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_dynamic_array2.sol

@@ -0,0 +1,11 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2 x;
+    }
+    struct MyStructName2 {
+        MyStructName1[] x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_dynamic_array3.sol

@@ -0,0 +1,11 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2[] x;
+    }
+    struct MyStructName2 {
+        MyStructName1[] x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_dynamic_multi_array.sol

@@ -0,0 +1,21 @@
+contract Test {
+    struct S1 {
+        S2[1][] x;
+    }
+    struct S2 {
+        S1 x;
+    }
+    struct T1 {
+        T2[][1] x;
+    }
+    struct T2 {
+        T1 x;
+    }
+    struct R1 {
+        R2[][] x;
+    }
+    struct R2 {
+        R1 x;
+    }
+}
+// ----

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_fixed_array1.sol

@@ -0,0 +1,12 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2[1] x;
+    }
+    struct MyStructName2 {
+        MyStructName1 x;
+    }
+}
+// ----
+// TypeError: (20-121): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_fixed_array2.sol

@@ -0,0 +1,12 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2 x;
+    }
+    struct MyStructName2 {
+        MyStructName1[1] x;
+    }
+}
+// ----
+// TypeError: (20-118): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_fixed_array3.sol

@@ -0,0 +1,12 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2[1] x;
+    }
+    struct MyStructName2 {
+        MyStructName1[1] x;
+    }
+}
+// ----
+// TypeError: (20-121): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_indirectly_recursive_fixed_multi_array.sol

@@ -0,0 +1,12 @@
+contract Test {
+    struct MyStructName1 {
+        address addr;
+        uint256 count;
+        MyStructName2[1][1] x;
+    }
+    struct MyStructName2 {
+        MyStructName1 x;
+    }
+}
+// ----
+// TypeError: (20-124): Recursive struct definition.

test/libsolidity/syntaxTests/structs/recursion/struct_definition_not_really_recursive_array.sol

@@ -0,0 +1,4 @@
+contract Test {
+    struct S1 { uint a; }
+    struct S2 { S1[1] x; S1[1] y; }
+}