add test (see #1810)

tests/unit/issues/Issue1810.hx

@@ -0,0 +1,26 @@
+package unit.issues;
+
+private abstract A(T) to T {
+	public inline function new(x:T) this = x;
+	public function get() return this;
+}
+
+private abstract T(X) from X to X {
+	public inline function new(x:X) this = x;
+	@:from public static inline function fromArr(x:Array<Int>) return new T(new X(x[0]));
+	public function get() return this;
+}
+
+private class X {
+	public var i:Int;
+	public function new(i:Int) {
+		this.i = i;
+	}
+}
+
+class Issue1810 extends Test {
+	function test() {
+		var a = new A([12]);
+		//eq(12, a.get().get().i);
+	}
+}