compiler: support creating pointers to struct

Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>

pkg/compiler/pointer_test.go

@@ -0,0 +1,18 @@
+package compiler_test
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestAddressOfLiteral(t *testing.T) {
+	src := `package foo
+	type Foo struct { A int	}
+	func Main() int {
+		f := &Foo{}
+		setA(f, 3)
+		return f.A
+	}
+	func setA(s *Foo, a int) { s.A = a }`
+	eval(t, src, big.NewInt(3))
+}