Sort tests.

test/libsolidity/semanticTests/structs/struct_delete_member.sol

@@ -0,0 +1,20 @@
+contract test {
+    struct testStruct {
+        uint256 m_value;
+    }
+    testStruct data1;
+
+    constructor() public {
+        data1.m_value = 2;
+    }
+
+    function deleteMember() public returns (uint256 ret_value) {
+        testStruct storage x = data1; //should not copy the data. data1.m_value == 2 but x.m_value = 0
+        x.m_value = 4;
+        delete x.m_value;
+        ret_value = data1.m_value;
+    }
+}
+
+// ----
+// deleteMember() -> 0