Imported Upstream version 3.6.0

Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14

mcs/tests/test-213.cs

@@ -0,0 +1,24 @@
+using System;
+
+class MyTest {
+	public static void Main(String[] args) {
+		S s1 = new S(11);
+		I s2 = s1;                          // Implicit boxing S-->I
+		S s3 = (S)s2;                       // Explicit unboxing I-->S
+		s3.Print();                         // Should print 11, does not
+	}
+}
+
+interface I {
+	void Print();
+}
+
+struct S : I {
+	public int i;
+	public S(int i) { 
+		this.i = i;
+	}
+	public void Print() {
+		Console.WriteLine(i);
+	}
+}