ported rewrite2 to c3

test/test_bitsruct.c3

@@ -0,0 +1,14 @@
+bitstruct Bits : uint {
+	bool a : 0;
+	bool b : 1;
+	bool c : 2;
+}
+
+fn int main()
+{
+	Bits a = {false, true, false};
+	Bits b = {true, true, false};
+	Bits c = a | b;
+
+	return 0;
+}

test/test_union.c3

@@ -0,0 +1,26 @@
+
+struct CmdA {
+	int a, b;
+}
+
+struct CmdB {
+	float a, b;
+}
+
+union AnyCmd {
+	CmdA a;
+	CmdB b;
+}
+
+struct Cmd {
+	int type;
+	AnyCmd cmd;
+}
+
+fn int main()
+{
+	Cmd c;
+	c.type = 1;
+	c.cmd.a = {.a = 1, .b = 2};
+	return 0;
+}

test/test_vtree.c3

@@ -0,0 +1,7 @@
+import std::io;
+import vtree;
+
+fn int main()
+{
+    return 0;
+}