Structs Test:
new SimpleStruct ()
new PublicStruct ()
new StructWithCreationMethod ()
StructWithCreationMethod
new StructWithNamedCreationMethod ()
StructWithNamedCreationMethod
new SimpleStruct () { field = 1 }
simple_struct.field = 1
test_in_parameter: st.field = 1
test_ref_parameter: st.field = 1
after test_ref_parameter: st.field = 2
after test_out_parameter: st.field = 3
.