[test] Added test. Closes #4388

tests/unit/src/unit/issues/Issue4388.hx

@@ -0,0 +1,22 @@
+package unit.issues;
+import haxe.Int64;
+
+class Issue4388 extends Test
+{
+	public function test()
+	{
+		var test = new PTest();
+		test.x |= 2;
+		t(test.x == 3);
+	}
+}
+
+private class PTest
+{
+	public var x(default, set) : Int64;
+	inline function set_x(i:Int64) : Int64 {
+		return this.x = i;
+	}
+
+	public function new() { this.x = 1; }
+}