Add test for broken cp50220 transcode behavior

See jruby#42

test/org/jcodings/transcode/TestCP51932ToCP50220.java

@@ -0,0 +1,24 @@
+package org.jcodings.transcode;
+
+import org.jcodings.Ptr;
+import org.junit.Test;
+import org.junit.Assert;
+import java.util.Arrays;
+
+public class TestCP51932ToCP50220 {
+    @Test
+    public void testCP51932ToCP50220() throws Exception {
+        byte[] src = "\u0000\u007F\u008E\u00A1\u008E\u00FE\u00A1\u00A1\u00A1\u00FE".getBytes("iso-8859-1");
+        byte[] dst = new byte[100];
+        Ptr srcPtr = new Ptr(0);
+        Ptr dstPtr = new Ptr(0);
+        EConv econv = TranscoderDB.open("CP51932", "CP50220", 0);
+        econv.convert(src, srcPtr, src.length, dst, dstPtr, dst.length, 0);
+
+        byte[] str = Arrays.copyOf(dst, dstPtr.p);
+
+        byte[] expected = "\u0000\u007F\u001B\u0024\u0042\u0021\u0023\u0050\u0000\u0021\u0021\u0021\u007E\u001B\u0028\u0042".getBytes("iso-8859-1");
+        byte[] actual = Arrays.copyOf(dst, dstPtr.p);
+        Assert.assertEquals(new String(expected), new String(actual));
+    }
+}