ICU-20374 need unum_close in new TestParseCases
diff --git a/icu4c/source/test/cintltst/cnumtst.c b/icu4c/source/test/cintltst/cnumtst.c
index 8ecab85..9520bfe 100644
--- a/icu4c/source/test/cintltst/cnumtst.c
+++ b/icu4c/source/test/cintltst/cnumtst.c
@@ -3166,6 +3166,8 @@
                     u_errorName(itemPtr->decStatus), itemPtr->decPos, itemPtr->decString,
                     u_errorName(status), parsePos, decstr);
         }
+
+        unum_close(unumDec);
     }
 }