migrate all the temporary tests to new test file

test/cases3/struct.zig

@@ -0,0 +1,30 @@
+const StructWithNoFields = struct {
+    fn add(a: i32, b: i32) -> i32 { a + b }
+};
+const empty_global_instance = StructWithNoFields {};
+
+fn callStructStaticMethod() {
+    @setFnTest(this);
+    const result = StructWithNoFields.add(3, 4);
+    assert(result == 7);
+}
+
+fn returnEmptyStructInstance() -> StructWithNoFields {
+    @setFnTest(this);
+    return empty_global_instance;
+}
+
+const should_be_11 = StructWithNoFields.add(5, 6);
+
+fn invokeStaticMethodInGlobalScope() {
+    @setFnTest(this);
+    assert(should_be_11 == 11);
+}
+
+
+
+// TODO const assert = @import("std").debug.assert;
+fn assert(ok: bool) {
+    if (!ok)
+        @unreachable();
+}